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Sample records for image correlation applied

  1. Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

    Science.gov (United States)

    Gradl, Paul R.

    2016-01-01

    Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

  2. Correlation-Peak Imaging

    Science.gov (United States)

    Ziegler, A.; Metzler, A.; Köckenberger, W.; Izquierdo, M.; Komor, E.; Haase, A.; Décorps, M.; von Kienlin, M.

    1996-08-01

    Identification and quantitation in conventional1H spectroscopic imagingin vivois often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, β-glucose, glutamine/glutamate, lysine, and arginine.

  3. Correlation peak analysis applied to a sequence of images using two different filters for eye tracking model

    Science.gov (United States)

    Patrón, Verónica A.; Álvarez Borrego, Josué; Coronel Beltrán, Ángel

    2015-09-01

    Eye tracking has many useful applications that range from biometrics to face recognition and human-computer interaction. The analysis of the characteristics of the eyes has become one of the methods to accomplish the location of the eyes and the tracking of the point of gaze. Characteristics such as the contrast between the iris and the sclera, the shape, and distribution of colors and dark/light zones in the area are the starting point for these analyses. In this work, the focus will be on the contrast between the iris and the sclera, performing a correlation in the frequency domain. The images are acquired with an ordinary camera, which with were taken images of thirty-one volunteers. The reference image is an image of the subjects looking to a point in front of them at 0° angle. Then sequences of images are taken with the subject looking at different angles. These images are processed in MATLAB, obtaining the maximum correlation peak for each image, using two different filters. Each filter were analyzed and then one was selected, which is the filter that gives the best performance in terms of the utility of the data, which is displayed in graphs that shows the decay of the correlation peak as the eye moves progressively at different angle. This data will be used to obtain a mathematical model or function that establishes a relationship between the angle of vision (AOV) and the maximum correlation peak (MCP). This model will be tested using different input images from other subject not contained in the initial database, being able to predict angle of vision using the maximum correlation peak data.

  4. Correlation plenoptic imaging

    CERN Document Server

    D'Angelo, Milena; Pepe, Francesco V; Vaccarelli, Ornella; Scarcelli, Giuliano

    2016-01-01

    Plenoptic imaging is a promising optical modality that simultaneously captures the location and the propagation direction of light in order to enable tridimensional imaging in a single shot. However, in classical imaging systems, the maximum spatial and angular resolutions are fundamentally linked; thereby, the maximum achievable depth of field is inversely proportional to the spatial resolution. We propose to take advantage of the second-order correlation properties of light to overcome this fundamental limitation. In this paper, we demonstrate that the momentum/position correlation of chaotic light leads to the enhanced refocusing power of correlation plenoptic imaging with respect to standard plenoptic imaging.

  5. Correlation Plenoptic Imaging

    Science.gov (United States)

    D'Angelo, Milena; Pepe, Francesco V.; Garuccio, Augusto; Scarcelli, Giuliano

    2016-06-01

    Plenoptic imaging is a promising optical modality that simultaneously captures the location and the propagation direction of light in order to enable three-dimensional imaging in a single shot. However, in standard plenoptic imaging systems, the maximum spatial and angular resolutions are fundamentally linked; thereby, the maximum achievable depth of field is inversely proportional to the spatial resolution. We propose to take advantage of the second-order correlation properties of light to overcome this fundamental limitation. In this Letter, we demonstrate that the correlation in both momentum and position of chaotic light leads to the enhanced refocusing power of correlation plenoptic imaging with respect to standard plenoptic imaging.

  6. Deep reflection seismic imaging in SE Poland using extended correlation method applied to PolandSPAN™ data

    Science.gov (United States)

    Malinowski, M.

    2016-10-01

    Here I apply the extended correlation technique to a 156-km long regional seismic profile, PL1-5100, from the PolandSPAN™ survey located in SE Poland. This method allows the extension of the nominal record length of the survey (12 s in this case) to much longer times (22 s tested here), given that in the field the raw uncorrelated data were stored and a broadband sweep was used. Processing of the ground force correlated data compared to pilot sweep correlated one produced qualitatively similar results. Based on the consistency of the ground force measured along the profile, data were correlated with the mean of the ground force estimates. Results of the processing were validated against the coincident wide-angle reflection/refraction (WARR) profile (CELEBRATION 2000 CEL05 profile) and a deep reflection profile located further to the SE (POLCRUST-01 profile). I found a good correspondence between the wide-angle Moho signature and the near-vertical incidence (NVI) Moho reflectivity, both in terms of the depth and the reflection strength, with the exception of the area of the crustal keel (Moho > 50 km) interpreted from the WARR data, where the NVI reflectivity is observed at depth ca. 47 km. Similarly to POLCRUST-01, line PL1-5100 is portraying the attenuated crust of the East European Platform margin with the dipping crystalline basement down to ca. 20 km depth and the reflective lower crust. Two important fault zones: Izbica-Zamość Fault and Wilczopole Fault Zone are interpreted as the deeply-rooted crustal features, but there is no evidence for the Teisseyre-Tornquist Zone itself.

  7. Applying the digital-image-correlation technique to measure the deformation of an old building’s column retrofitted with steel plate in an in situ pushover test

    Indian Academy of Sciences (India)

    Shih-Heng Tung; Ming-Hsiang Shih; Wen-Pei Sung

    2014-06-01

    An in situ pushover test is carried out on an old building of Guan-Miao elementary school in south Taiwan. Columns of this building are seismically retrofitted with steel plate. The DIC (digital-image-correlation) technique is used to measure the deformation of the retrofitted column. The result shows that the DIC technique can be successfully applied to measure the relative displacement of the column. Additionally, thismethod leads to the measurement of relative displacements formany points on the column simultaneously. Hence, the column deformation curve, rotation and curvature can be determined using interpolation method. The resulting curvaturediagram reveals that the phenomenon of plastic hinge occurs at about 2% storey drift ratio, and that the DIC technique can be applied to measure column deformation in a full scale in situ test.

  8. Progressive Wavelet Correlation for Image Recognition

    OpenAIRE

    Stojanovic, Igor

    2013-01-01

    An algorithm for recognition and retrieval of image from image collection is developed. Basis of the algorithm is the progressive wavelet correlation. The final result is the recognition and retrieval of the wanted image, if it is in the image collection. Instructions for the choice of correlation threshold value for obtaining desired results are defined. The areas where the algorithm can be applied are also discussed. To increase efficiency is presented two phases solution. The first phase u...

  9. Correlation spectroscopy applied to glycerol polyester spectra

    Science.gov (United States)

    The recent development of glycerol polyesters for use as controlled release matrix materials in the nutraceuticals and pharmaceuticals industries presented a unique opportunity to apply correlation spectroscopy. In a typical formulation the glycerol is reacted with a polyfunctional acid such as citr...

  10. Concordance correlation coefficient applied to discrete data.

    Science.gov (United States)

    Carrasco, Josep L; Jover, Lluis

    2005-12-30

    In any field in which decisions are subject to measurements, interchangeability between the methods used to obtain these measurements is essential. To consider methods as interchangeable, a certain degree of agreement is needed between the measurements they provide. The concordance correlation coefficient is an index that assesses the strength of agreement and it has been widely applied in situations in which measurements are made on a continuous scale. Recently the concordance correlation coefficient has been defined as a specific intraclass correlation coefficient estimated by the variance components of a Normal-Normal mixed linear model. Although this coefficient was defined for the continuous scale case, it may also be used with a discrete scale. In this case the data are often transformed and normalized, and the concordance correlation is applied. This study discusses the expression of the concordance correlation coefficient for discrete Poisson data by means of the Poisson-Normal generalized linear mixed model. The behaviour of the concordance correlation coefficient estimate is assessed by means of a simulation study, in which the estimates were compared using four models: three Normal-Normal mixed models with raw data, log-transformed data and square-root transformed data, and the Poisson-Normal generalized linear mixed model. An example is provided in which two different methods are used to measure CD34+ cells.

  11. Improved Digital Image Correlation method

    Science.gov (United States)

    Mudassar, Asloob Ahmad; Butt, Saira

    2016-12-01

    Digital Image Correlation (DIC) is a powerful technique which is used to correlate two image segments to determine the similarity between them. A correlation image is formed which gives a peak known as correlation peak. If the two image segments are identical the peak is known as auto-correlation peak otherwise it is known as cross correlation peak. The location of the peak in a correlation image gives the relative displacement between the two image segments. Use of DIC for in-plane displacement and deformation measurements in Electronic Speckle Photography (ESP) is well known. In ESP two speckle images are correlated using DIC and relative displacement is measured. We are presenting background review of ESP and disclosing a technique based on DIC for improved relative measurements which we regard as the improved DIC method. Simulation and experimental results reveal that the proposed improved-DIC method is superior to the conventional DIC method in two aspects, in resolution and in the availability of reference position in displacement measurements.

  12. Super Resolution Imaging Applied to Scientific Images

    Science.gov (United States)

    2007-05-01

    investigator, (3) development of Papoulis -Gerchberg method to implement the analytic continuation of spectral details, (4) exploration of contourlet and...off with noise present in the observation. In [30] we make use of Papoulis -Gerchberg algorithm of signal extrapolation to perform Image super...we have used a training database consisting of high resolution images. For Papoulis -Gerchberg method number of iterations and the filter used both

  13. Optical correlator techniques applied to robotic vision

    Science.gov (United States)

    Hine, Butler P., III; Reid, Max B.; Downie, John D.

    1991-01-01

    Vision processing is one of the most computationally intensive tasks required of an autonomous robot. The data flow from a single typical imaging sensor is roughly 60 Mbits/sec, which can easily overload current on-board processors. Optical correlator-based processing can be used to perform many of the functions required of a general robotic vision system, such as object recognition, tracking, and orientation determination, and can perform these functions fast enough to keep pace with the incoming sensor data. We describe a hybrid digital electronic/analog optical robotic vision processing system developed at Ames Research Center to test concepts and algorithms for autonomous construction, inspection, and maintenance of space-based habitats. We discuss the system architecture design and implementation, its performance characteristics, and our future plans. In particular, we compare the performance of the system to a more conventional all digital electronic system developed concurrently. The hybrid system consistently outperforms the digital electronic one in both speed and robustness.

  14. Edge-based correlation image registration for multispectral imaging

    Science.gov (United States)

    Nandy, Prabal [Albuquerque, NM

    2009-11-17

    Registration information for images of a common target obtained from a plurality of different spectral bands can be obtained by combining edge detection and phase correlation. The images are edge-filtered, and pairs of the edge-filtered images are then phase correlated to produce phase correlation images. The registration information can be determined based on these phase correlation images.

  15. Applied medical image processing a basic course

    CERN Document Server

    Birkfellner, Wolfgang

    2014-01-01

    A widely used, classroom-tested text, Applied Medical Image Processing: A Basic Course delivers an ideal introduction to image processing in medicine, emphasizing the clinical relevance and special requirements of the field. Avoiding excessive mathematical formalisms, the book presents key principles by implementing algorithms from scratch and using simple MATLAB®/Octave scripts with image data and illustrations on an accompanying CD-ROM or companion website. Organized as a complete textbook, it provides an overview of the physics of medical image processing and discusses image formats and data storage, intensity transforms, filtering of images and applications of the Fourier transform, three-dimensional spatial transforms, volume rendering, image registration, and tomographic reconstruction.

  16. Spatial correlation coefficient images for ultrasonic detection.

    Science.gov (United States)

    Cepel, Raina; Ho, K C; Rinker, Brett A; Palmer, Donald D; Lerch, Terrence P; Neal, Steven P

    2007-09-01

    In ultrasonics, image formation and detection are generally based on signal amplitude. In this paper, we introduce correlation coefficient images as a signal-amplitude independent approach for image formation. The correlation coefficients are calculated between A-scans digitized at adjacent measurement positions. In these images, defects are revealed as regions of high or low correlation relative to the background correlations associated with noise. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular ring and crack detection in an aluminum aircraft structure.

  17. Discrete-cosine-transform-based image compression applied to dermatology

    Science.gov (United States)

    Cookson, John P.; Sneiderman, Charles; Rivera, Christopher

    1991-05-01

    The research reported in this paper concerns an evaluation of the impact of compression on the quality of digitized color dermatologic images. 35 mm slides of four morphologic types of skin lesions were captured at 1000 pixels per inch (ppi) in 24 bit RGB color, to give an approximate 1K X 1K image. The discrete cosine transform (DCT) algorithm, was applied to the resulting image files to achieve compression ratios of about 7:1, 28:1, and 70:1. The original scans and the decompressed files were written to a 35 mm film recorder. Together with the original photo slides, the slides resulting from digital images were evaluated in a study of morphology recognition and image quality assessment. A panel of dermatologists was asked to identify the morphology depicted and to rate the image quality of each slide. The images were shown in a progression from highest level of compression to original photo slides. We conclude that the use of DCT file compression yields acceptable performance for skin lesion images since differences in morphology recognition performance do not correlate significantly with the use of original photos versus compressed versions. Additionally, image quality evaluation does not correlate significantly with level of compression.

  18. Correlation Plenoptic Imaging With Entangled Photons

    CERN Document Server

    Pepe, Francesco V; Garuccio, Augusto; Scarcelli, Giuliano; D'Angelo, Milena

    2016-01-01

    Plenoptic imaging is a novel optical technique for three-dimensional imaging in a single shot. It is enabled by the simultaneous measurement of both the location and the propagation direction of light in a given scene. In the standard approach, the maximum spatial and angular resolutions are inversely proportional, and so are the resolution and the maximum achievable depth of focus of the 3D image. We have recently proposed a method to overcome such fundamental limits by combining plenoptic imaging with an intriguing correlation remote-imaging technique: ghost imaging. Here, we theoretically demonstrate that correlation plenoptic imaging can be effectively achieved by exploiting the position-momentum entanglement characterizing spontaneous parametric down-conversion (SPDC) photon pairs. As a proof-of-principle demonstration, we shall show that correlation plenoptic imaging with entangled photons may enable the refocusing of an out-of-focus image at the same depth of focus of a standard plenoptic device, but w...

  19. Correlation Imaging with Arbitrary Sampling Trajectories

    Science.gov (United States)

    Li, Yu

    2014-01-01

    The presented work aims to develop a generalized linear approach to image reconstruction with arbitrary sampling trajectories for high-speed MRI. This approach is based on a previously developed image reconstruction framework, "correlation imaging" (1). In the presented work, correlation imaging with arbitrary sampling trajectories is implemented in a multi-dimensional hybrid space that is formed from the physical sampling space and a virtually defined space. By introducing an undersampling trajectory with both uniformity and randomness in the hybrid space, correlation imaging may take advantage of multiple image reconstruction mechanisms including coil sensitivity encoding, data sparsity and information sharing. This hybrid-space implementation is demonstrated in multi-slice 2D imaging, multi-scan imaging, and radial dynamic imaging. Since more information is used in image reconstruction, it is found that hybrid-space correlation imaging outperforms several conventional techniques. The presented approach will benefit clinical MRI by enabling correlation imaging to be used to accelerate multi-scan clinical protocols that need different sampling trajectories in different scans. PMID:24629517

  20. Hot Stuff? Thermal Imaging Applied to Cryocrystallography

    Science.gov (United States)

    Snell, E. H.

    2004-01-01

    In the past we have used thermal imaging techniques to visualize the cryocooling processes of macromolecular crystals. From these images it was clear that a cold wave progresses through a crystal starting at the face closest to the origin of the cold stream and ending at the point furthest away. During these studies we used large volume crystals, which were clearly distinguished fiom the loop holding them. These large crystals, originally grown for neutron diffiaction studies, were chosen deliberately to enhance the imaging. As an extension to this work, we present used thermal imaging to study small crystals, held in a cryo-loop, in the presence of vitrified mother liquor. The different d a r e d transmission and reflectance properties of the crystal in comparison to the mother liquor surrounding it are thought to be the parameter that produces the contrast that makes the crystal visible. An application of this technology may be the determination of the exact location of small crystals in a cryo-loop. Data fkom initial tests in support of application development was recorded for lysozyme crystals and for bFGF/dna complex crystals, which were cryocooled and imaged in large loops, both with visible light mad with h i k e d rdi&tion. The crystals were clearly distinguished from the vitrified solution in the infiared spectrum, while in the case of the bFGF/dna complex the illumination had to be carefully manipulated to make the crystal visible in the visible spectrum. These results suggest that the thermal imaging may be more sensitive than visual imaging for automated location of small crystals. However, further work on small crystals robotically mounted at SSRL did not clearly visualize those crystals. The depth of field of the camera proved to be limiting and a different cooling geometry was used, compared to the previous, successful experiments. Analysis to exploit multiple images to improve depth of field and experimental work to understand cooling geometry

  1. Color-image retrieval based on fuzzy correlation

    Institute of Scientific and Technical Information of China (English)

    ZHAI Hongchen; LIANG Yanmei; MU Guoguang

    2004-01-01

    We report a method of color-image retrieval based on fuzzy correlation, in which α-cut relations in fuzzy set theory are applied to defining color match and height match of color peaks for synthesizing fuzzy correlation of two color histograms, and RGB space is partitioned into six sub-regions in the experiment for the regional color comparisons. Experimental results show that the efficiency of the color-image retrieval can be effectively improved by this approach.

  2. Trigeminal nerve: Anatomic correlation with MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, D.L.; Pech, P.; Pojunas, K.W.; Kilgore, D.P.; Williams, A.L.; Haughton, V.M.

    1986-06-01

    Through correlation with cryomicrotic sections, the appearance of the trigeminal nerve and its branches on magnetic resonance images is described in healthy individuals and in patients with tumors involving this nerve. Coronal images are best for defining the different parts of the nerve and for making a side-to-side comparison. Sagittal images are useful to demonstrate tumors involving the Gasserian ganglion.

  3. Hyperspectral imaging applied to forensic medicine

    Science.gov (United States)

    Malkoff, Donald B.; Oliver, William R.

    2000-03-01

    Remote sensing techniques now include the use of hyperspectral infrared imaging sensors covering the mid-and- long wave regions of the spectrum. They have found use in military surveillance applications due to their capability for detection and classification of a large variety of both naturally occurring and man-made substances. The images they produce reveal the spatial distributions of spectral patterns that reflect differences in material temperature, texture, and composition. A program is proposed for demonstrating proof-of-concept in using a portable sensor of this type for crime scene investigations. It is anticipated to be useful in discovering and documenting the affects of trauma and/or naturally occurring illnesses, as well as detecting blood spills, tire patterns, toxic chemicals, skin injection sites, blunt traumas to the body, fluid accumulations, congenital biochemical defects, and a host of other conditions and diseases. This approach can significantly enhance capabilities for determining the circumstances of death. Potential users include law enforcement organizations (police, FBI, CIA), medical examiners, hospitals/emergency rooms, and medical laboratories. Many of the image analysis algorithms already in place for hyperspectral remote sensing and crime scene investigations can be applied to the interpretation of data obtained in this program.

  4. Image automatic mosaics based on contour phase correlation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; HU Zhiping; LIU Zhitai; OU Zongying

    2007-01-01

    The image planar mosaics is studied,and an image automatic mosaics algorithm on the basis of contour phase correlation is proposed in this paper.To begin with,by taking into account mere translations and rotations between images,a contour phase correlation algorithm is used to realize the preliminary alignments of images,and the initial projective transformation matrices are obtained.Then,an optimization algorithm is used to optimize the initial projective transformation matrices,and complete the precise image mosaics.The contour phase correlation is an improvement on the conventional phase correlation in two aspects:First,the contours of images are extracted,and the phase correlation is applied to the contours of images instead of the whole original images;Second,when there are multiple peak values approximate to the maximum peak value in the δ function array,their corresponding translations can be regarded as candidate translations and calculated separately,and the best translation can be determined by the optimization of conformability of two images in the overlapping area.The running results show that the proposed algorithm can consistently yield high-quality mosaics,even in the cases of poor or differential lighting conditions,existences of minor rotations,and other complicated displacements between images.

  5. Rainbow correlation imaging with macroscopic twin beam

    Science.gov (United States)

    Allevi, Alessia; Bondani, Maria

    2017-06-01

    We present the implementation of a correlation-imaging protocol that exploits both the spatial and spectral correlations of macroscopic twin-beam states generated by parametric downconversion. In particular, the spectral resolution of an imaging spectrometer coupled to an EMCCD camera is used in a proof-of-principle experiment to encrypt and decrypt a simple code to be transmitted between two parties. In order to optimize the trade-off between visibility and resolution, we provide the characterization of the correlation images as a function of the spatio-spectral properties of twin beams generated at different pump power values.

  6. Neurocysticercosis: Correlative pathomorphology and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, J.; Hewlett, R.; Alheit, B.; Bowen, R.

    1988-02-01

    CT and MR images of 32 patients with neurocysticercosis were correlated with pathomorphology. Gross morphological features of cystic larvae, complex arachnoid cysts, granulomatous abscesses, basal meningitis and mineralised nodules correlated closely with the images obtained, especially on MR, where resolution permitted visualisation of larval protoscolices. Our material indicates three forms of the natural history of neurocysticercosis related chiefly to anatomic location, and provides details of the evolution of large, complex arachnoid cysts.

  7. Correlation Plenoptic Imaging With Entangled Photons

    Directory of Open Access Journals (Sweden)

    Francesco V. Pepe

    2016-06-01

    Full Text Available Plenoptic imaging is a novel optical technique for three-dimensional imaging in a single shot. It is enabled by the simultaneous measurement of both the location and the propagation direction of light in a given scene. In the standard approach, the maximum spatial and angular resolutions are inversely proportional, and so are the resolution and the maximum achievable depth of focus of the 3D image. We have recently proposed a method to overcome such fundamental limits by combining plenoptic imaging with an intriguing correlation remote-imaging technique: ghost imaging. Here, we theoretically demonstrate that correlation plenoptic imaging can be effectively achieved by exploiting the position-momentum entanglement characterizing spontaneous parametric down-conversion (SPDC photon pairs. As a proof-of-principle demonstration, we shall show that correlation plenoptic imaging with entangled photons may enable the refocusing of an out-of-focus image at the same depth of focus of a standard plenoptic device, but without sacrificing diffraction-limited image resolution.

  8. Advanced methods for image registration applied to JET videos

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, Teddy, E-mail: teddy.craciunescu@jet.uk [EURATOM-MEdC Association, NILPRP, Bucharest (Romania); Murari, Andrea [Consorzio RFX, Associazione EURATOM-ENEA per la Fusione, Padova (Italy); Gelfusa, Michela [Associazione EURATOM-ENEA – University of Rome “Tor Vergata”, Roma (Italy); Tiseanu, Ion; Zoita, Vasile [EURATOM-MEdC Association, NILPRP, Bucharest (Romania); Arnoux, Gilles [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom)

    2015-10-15

    Graphical abstract: - Highlights: • Development of an image registration method for JET IR and fast visible cameras. • Method based on SIFT descriptors and coherent point drift points set registration technique. • Method able to deal with extremely noisy images and very low luminosity images. • Computation time compatible with the inter-shot analysis. - Abstract: The last years have witnessed a significant increase in the use of digital cameras on JET. They are routinely applied for imaging in the IR and visible spectral regions. One of the main technical difficulties in interpreting the data of camera based diagnostics is the presence of movements of the field of view. Small movements occur due to machine shaking during normal pulses while large ones may arise during disruptions. Some cameras show a correlation of image movement with change of magnetic field strength. For deriving unaltered information from the videos and for allowing correct interpretation an image registration method, based on highly distinctive scale invariant feature transform (SIFT) descriptors and on the coherent point drift (CPD) points set registration technique, has been developed. The algorithm incorporates a complex procedure for rejecting outliers. The method has been applied for vibrations correction to videos collected by the JET wide angle infrared camera and for the correction of spurious rotations in the case of the JET fast visible camera (which is equipped with an image intensifier). The method has proved to be able to deal with the images provided by this camera frequently characterized by low contrast and a high level of blurring and noise.

  9. Speckle pattern processing by digital image correlation

    Directory of Open Access Journals (Sweden)

    Gubarev Fedor

    2016-01-01

    Full Text Available Testing the method of speckle pattern processing based on the digital image correlation is carried out in the current work. Three the most widely used formulas of the correlation coefficient are tested. To determine the accuracy of the speckle pattern processing, test speckle patterns with known displacement are used. The optimal size of a speckle pattern template used for determination of correlation and corresponding the speckle pattern displacement is also considered in the work.

  10. Coherent photoacoustic-ultrasound correlation and imaging.

    Science.gov (United States)

    Gao, Fei; Feng, Xiaohua; Zheng, Yuanjin

    2014-09-01

    Both photoacoustics and ultrasound have been researched extensively but separately. In this letter, we report an initial study on the coherent correlation between pulsed photoacoustic wave and pulse-echo ultrasound wave. By illuminating an object with a pulsed laser and external ultrasound sequentially, both the endogenous photoacoustic wave and pulse-echo ultrasound wave are received and coherently correlated, demonstrating enhanced signal-to-noise ratio. Image contrast of the proposed coherent photoacoustic-ultrasound imaging is also demonstrated to be improved significantly on vessel-mimicking phantom, due to fusion of the optical absorption and ultrasound reflection contrasts by coherent correlation of either conventional laser-induced photoacoustic imaging or pulse-echo ultrasound imaging separately.

  11. Image Correlation Microscopy for Uniform Illumination

    Science.gov (United States)

    Gaborski, Thomas R.; Sealander, Michael N.; Ehrenberg, Morton; Waugh, Richard E.; McGrath, James L.

    2011-01-01

    Image cross-correlation microscopy (ICM) is a technique that quantifies the motion of fluorescent features in an image by measuring the temporal autocorrelation function decay in a time-lapse image sequence. ICM has traditionally employed laser-scanning microscopes because the technique emerged as an extension of laser-based fluorescence correlation spectroscopy (FCS). In this work, we show that image correlation can also be used to measure fluorescence dynamics in uniform illumination or wide-field imaging systems and we call our new approach uniform illumination image correlation microscopy (UI-ICM). Wide-field microscopy is not only a simpler, less expensive imaging modality, but it offers the capability of greater temporal resolution over laser-scanning systems. In traditional laser-scanning ICM, lateral mobility is calculated from the temporal de-correlation of an image, where the characteristic length is the illuminating laser beam width. In wide-field microscopy, the diffusion length is defined by the feature size using the spatial autocorrelation function (SACF). Correlation function decay in time occurs as an object diffuses from its original position. We show that theoretical and simulated comparisons between Gaussian and uniform features indicate the temporal autocorrelation function (TACF) depends strongly on particle size and not particle shape. In this report, we establish the relationships between the SACF feature size, TACF characteristic time and the diffusion coefficient for UI-ICM using analytical, Monte-Carlo and experimental validation with particle tracking algorithms. Additionally, we demonstrate UI-ICM analysis of adhesion molecule domain aggregation and diffusion on the surface of human neutrophils. PMID:20055917

  12. Phase Correlation Based Iris Image Registration Model

    Institute of Scientific and Technical Information of China (English)

    Jun-Zhou Huang; Tie-Niu Tan; Li Ma; Yun-Hong Wang

    2005-01-01

    Iris recognition is one of the most reliable personal identification methods. In iris recognition systems, image registration is an important component. Accurately registering iris images leads to higher recognition rate for an iris recognition system. This paper proposes a phase correlation based method for iris image registration with sub-pixel accuracy.Compared with existing methods, it is insensitive to image intensity and can compensate to a certain extent the non-linear iris deformation caused by pupil movement. Experimental results show that the proposed algorithm has an encouraging performance.

  13. Sidescan Sonar Image Matching Using Cross Correlation

    DEFF Research Database (Denmark)

    Thisen, Erik; Sørensen, Helge Bjarup Dissing; Stage, Bjarne

    2003-01-01

    When surveying an area for sea mines with a sidescan sonar, the ability to find the same object in two different sonar images is helpful to determine the nature of the object. The main problem with matching two sidescan sonar images is that a scene changes appearance when viewed from different...... viewpoints. This paper presents a novel approach for matching two sidescan sonar images. The method first registers the two images to ground, then uses the cross correlation of the object positions on the seabed to find the correct displacement between the two images. In order to correct any minor...... displacements of the relative objects position as a result of the ground registration, the object position is given an area of influence. The method is compared to an existing method for matching sidescan sonar images based on hypothetical reasoning. The two methods are compared on a number of real sidescan...

  14. Terahertz imaging applied to cancer diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Brun, M-A; Formanek, F; Yasuda, A [Life Science Laboratory, Advanced Materials Laboratories, Sony Corporation, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo-ku, Tokyo, 113-8510 (Japan); Sekine, M; Ando, N; Eishii, Y, E-mail: florian.formanek@jp.sony.co [Department of Human Pathology, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo-ku, Tokyo, 113-8510 (Japan)

    2010-08-21

    We report on terahertz (THz) time-domain spectroscopy imaging of 10 {mu}m thick histological sections. The sections are prepared according to standard pathological procedures and deposited on a quartz window for measurements in reflection geometry. Simultaneous acquisition of visible images enables registration of THz images and thus the use of digital pathology tools to investigate the links between the underlying cellular structure and specific THz information. An analytic model taking into account the polarization of the THz beam, its incidence angle, the beam shift between the reference and sample pulses as well as multiple reflections within the sample is employed to determine the frequency-dependent complex refractive index. Spectral images are produced through segmentation of the extracted refractive index data using clustering methods. Comparisons of visible and THz images demonstrate spectral differences not only between tumor and healthy tissues but also within tumors. Further visualization using principal component analysis suggests different mechanisms as to the origin of image contrast.

  15. Study of consolidating materials applied on wood by hyperspectral imaging

    Science.gov (United States)

    Bonifazi, G.; Serranti, S.; Capobianco, G.; Agresti, G.; Calienno, L.; Picchio, R.; Lo Monaco, A.; Santamaria, U.; Pelosi, C.

    2016-05-01

    The focus of this study was addressed to investigate the potentiality of HyperSpectral Imaging (HSI) in the monitoring of commercial consolidant products applied on wood samples. Poplar (Populus Sp.) and walnut (Juglans Regia L.) were chosen for the consolidant application. Both traditional and innovative products were selected, based on acrylic, epoxy and aliphatic compounds. Wood samples were stresses by freeze/thaw cycles in order to cause material degradation. Then the consolidants were applied under vacuum. The samples were finally artificially aged for 168 hours in a solar box chamber. The samples were acquired in the SWIR (1000-2500 nm) range by SISUChema XL™ device (Specim, Finland) after 168 hours of irradiation. As comparison, color measurement was also used as economic, simple and noninvasive technique to evaluate the deterioration and consolidation effects on wood. All data were then processed adopting a chemometric approach finalized to define correlation models, HSI based, between consolidating materials, wood species and short time ageing effects.

  16. Video stabilization with sub-image phase correlation

    Institute of Scientific and Technical Information of China (English)

    Juanjuan Zhu; Baolong Guo

    2006-01-01

    @@ A fast video stabilization method is presented,which consists of sub-image phase correlation based global motion estimation,Kalman filtering based motion smoothing and motion modification based compensation.Global motion is decided using phase correlation in four sub-images.Then,the motion vectors are accumulated to be Kalman filtered for smoothing.The ordinal motion compensation is applied to each frame with modification to prevent error propagation.Experimental results show that this stabilization system can remove unwanted translational jitter of video sequences and follow intentional scan at real-time speed.

  17. Iterative electromagnetic Born inversion applied to earth conductivity imaging

    Energy Technology Data Exchange (ETDEWEB)

    Alumbaugh, D.L.

    1993-08-01

    This thesis investigates the use of a fast imaging technique to deduce the spatial conductivity distribution in the earth from low frequency (< 1 MHz), cross well electromagnetic (EM) measurements. The theory embodied in this work is the extension of previous strategies and is based on the Born series approximation to solve both the forward and inverse problem. Nonlinear integral equations are employed to derive the series expansion which accounts for the scattered magnetic fields that are generated by inhomogeneities embedded in either a homogenous or a layered earth. A sinusoidally oscillating, vertically oriented magnetic dipole is employed as a source, and it is assumed that the scattering bodies are azimuthally symmetric about the source dipole axis. The use of this model geometry reduces the 3-D vector problem to a more manageable 2-D scalar form. The validity of the cross well EM method is tested by applying the imaging scheme to two sets of field data. Images of the data collected at the Devine, Texas test site show excellent correlation with the well logs. Unfortunately there is a drift error present in the data that limits the accuracy of the results. A more complete set of data collected at the Richmond field station in Richmond, California demonstrates that cross well EM can be successfully employed to monitor the position of an injected mass of salt water. Both the data and the resulting images clearly indicate the plume migrates toward the north-northwest. The plausibility of these conclusions is verified by applying the imaging code to synthetic data generated by a 3-D sheet model.

  18. APES Beamforming Applied to Medical Ultrasound Imaging

    DEFF Research Database (Denmark)

    Blomberg, Ann E. A.; Holfort, Iben Kraglund; Austeng, Andreas

    2009-01-01

    Recently, adaptive beamformers have been introduced to medical ultrasound imaging. The primary focus has been on the minimum variance (MV) (or Capon) beamformer. This work investigates an alternative but closely related beamformer, the Amplitude and Phase Estimation (APES) beamformer. APES offers...... added robustness at the expense of a slightly lower resolution. The purpose of this study was to evaluate the performance of the APES beamformer on medical imaging data, since correct amplitude estimation often is just as important as spatial resolution. In our simulations we have used a 3.5 MHz, 96...... element linear transducer array. When imaging two closely spaced point targets, APES displays nearly the same resolution as the MV, and at the same time improved amplitude control. When imaging cysts in speckle, APES offers speckle statistics similar to that of the DAS, without the need for temporal...

  19. OSA Imaging and Applied Optics Congress Support

    Science.gov (United States)

    2017-02-16

    contact our Grants Manager, Ewelina Osinska, at (202) 416-1934 or eosinska@osa.org. Sincerely, Marcia Lesky Deputy Senior Director Phone: 1-202-416...reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188) , 1215...applications from internationally recognized academic and industry leaders in the field. 1S. SUBJECT TERMS imaging, imaging systems, computational

  20. Digital image correlation: displacement accuracy estimation

    Directory of Open Access Journals (Sweden)

    Wattrisse B.

    2010-06-01

    Full Text Available The aim of this collaborative work is to study the uncertainties associated with Digital Image Correlation techniques (DIC. More specifically, the link between displacement uncertainties and several correlation parameters chosen by the user and relative to the image analysis software and several image characteristics like speckle size and image noise is emphasized. A previous work [1] has been done for situations with spatially fluctuating displacement fields which dealt with mismatch error linked to the discrepancy between the adopted shape function and the real displacement field in the subset. This present work is focused on the ultimate error regime. To ensure that there is no mismatch error, synthetic images of plane rigid body translation have been analysed. DIC softwares developed by or used in the French community were used to study a large number of settings. The first observations are: (a bias amplitude is almost always insensitive to the subset size, (b DIC formulations can be split up into two families. For the first one, the bias amplitude increases with the noise while it remains constant for the second one. For both families, the mean value of the random error increases with the noise level and with the inverse of the subset size. Furthermore, the random error decreases with the radius of the speckle for the first family, while it increases for the second one. These two different behaviours of the tested DIC package are probably due to their underlying DIC formulation (interpolation, correlation criteria, optimisation process.

  1. Spectroscopic Imaging of Strongly Correlated Electronic States

    Science.gov (United States)

    Yazdani, Ali; da Silva Neto, Eduardo H.; Aynajian, Pegor

    2016-03-01

    The study of correlated electronic systems from high-Tc cuprates to heavy-fermion systems continues to motivate the development of experimental tools to probe electronic phenomena in new ways and with increasing precision. In the past two decades, spectroscopic imaging with scanning tunneling microscopy has emerged as a powerful experimental technique. The combination of high energy and spatial resolutions provided by this technique reveals unprecedented detail of the electronic properties of strongly correlated metals and superconductors. This review examines specific experiments, theoretical concepts, and measurement methods that have established the application of these techniques to correlated materials. A wide range of applications, such as the study of collective responses to single atomic impurities, the characterization of quasiparticle-like excitations through their interference, and the identification of competing electronic phases using spectroscopic imaging, are discussed.

  2. Digital Image Correlation with Dynamic Subset Selection

    Science.gov (United States)

    Hassan, Ghulam Mubashar; MacNish, Cara; Dyskin, Arcady; Shufrin, Igor

    2016-09-01

    The quality of the surface pattern and selection of subset size play a critical role in achieving high accuracy in Digital Image Correlation (DIC). The subset size in DIC is normally selected by testing different subset sizes across the entire image, which is a laborious procedure. This also leads to the problem that the worst region of the surface pattern influences the performance of DIC across the entire image. In order to avoid these limitations, a Dynamic Subset Selection (DSS) algorithm is proposed in this paper to optimize the subset size for each point in an image before optimizing the correlation parameters. The proposed DSS algorithm uses the local pattern around the point of interest to calculate a parameter called the Intensity Variation Ratio (Λ), which is used to optimize the subset size. The performance of the DSS algorithm is analyzed using numerically generated images and is compared with the results of traditional DIC. Images obtained from laboratory experiments are also used to demonstrate the utility of the DSS algorithm. Results illustrate that the DSS algorithm provides a better alternative to subset size "guessing" and finds an appropriate subset size for each point of interest according to the local pattern.

  3. An improved image reconstruction method for optical intensity correlation Imaging

    Science.gov (United States)

    Gao, Xin; Feng, Lingjie; Li, Xiyu

    2016-12-01

    The intensity correlation imaging method is a novel kind of interference imaging and it has favorable prospects in deep space recognition. However, restricted by the low detecting signal-to-noise ratio (SNR), it's usually very difficult to obtain high-quality image of deep space object like high-Earth-orbit (HEO) satellite with existing phase retrieval methods. In this paper, based on the priori intensity statistical distribution model of the object and characteristics of measurement noise distribution, an improved method of Prior Information Optimization (PIO) is proposed to reduce the ambiguous images and accelerate the phase retrieval procedure thus realizing fine image reconstruction. As the simulations and experiments show, compared to previous methods, our method could acquire higher-resolution images with less error in low SNR condition.

  4. Changing image of correlation optics: introduction

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Desyatnikov, Anton S.; Gbur, Gregory J.;

    2016-01-01

    This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers. (C)...

  5. Changing image of correlation optics: introduction.

    Science.gov (United States)

    Angelsky, Oleg V; Desyatnikov, Anton S; Gbur, Gregory J; Hanson, Steen G; Lee, Tim; Miyamoto, Yoko; Schneckenburger, Herbert; Wyant, James C

    2016-04-20

    This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers.

  6. Changing image of correlation optics: introduction

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Desyatnikov, Anton S.; Gbur, Gregory J.

    2016-01-01

    This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers. (C...

  7. Computing dynamic classification images from correlation maps.

    Science.gov (United States)

    Lu, Hongjing; Liu, Zili

    2006-05-22

    We used Pearson's correlation to compute dynamic classification images of biological motion in a point-light display. Observers discriminated whether a human figure that was embedded in dynamic white Gaussian noise was walking forward or backward. Their responses were correlated with the Gaussian noise fields frame by frame, across trials. The resultant correlation map gave rise to a sequence of dynamic classification images that were clearer than either the standard method of A. J. Ahumada and J. Lovell (1971) or the optimal weighting method of R. F. Murray, P. J. Bennett, and A. B. Sekuler (2002). Further, the correlation coefficients of all the point lights were similar to each other when overlapping pixels between forward and backward walkers were excluded. This pattern is consistent with the hypothesis that the point-light walker is represented in a global manner, as opposed to a fixed subset of point lights being more important than others. We conjecture that the superior performance of the correlation map may reflect inherent nonlinearities in processing biological motion, which are incompatible with the assumptions underlying the previous methods.

  8. Automated Quality Assurance Applied to Mammographic Imaging

    Directory of Open Access Journals (Sweden)

    Anne Davis

    2002-07-01

    Full Text Available Quality control in mammography is based upon subjective interpretation of the image quality of a test phantom. In order to suppress subjectivity due to the human observer, automated computer analysis of the Leeds TOR(MAM test phantom is investigated. Texture analysis via grey-level co-occurrence matrices is used to detect structures in the test object. Scoring of the substructures in the phantom is based on grey-level differences between regions and information from grey-level co-occurrence matrices. The results from scoring groups of particles within the phantom are presented.

  9. Demosaicing images from colour cameras for digital image correlation

    Science.gov (United States)

    Forsey, A.; Gungor, S.

    2016-11-01

    Digital image correlation is not the intended use for consumer colour cameras, but with care they can be successfully employed in such a role. The main obstacle is the sparsely sampled colour data caused by the use of a colour filter array (CFA) to separate the colour channels. It is shown that the method used to convert consumer camera raw files into a monochrome image suitable for digital image correlation (DIC) can have a significant effect on the DIC output. A number of widely available software packages and two in-house methods are evaluated in terms of their performance when used with DIC. Using an in-plane rotating disc to produce a highly constrained displacement field, it was found that the bicubic spline based in-house demosaicing method outperformed the other methods in terms of accuracy and aliasing suppression.

  10. Application of the progressive wavelet correlation for image recognition and retrieval from the collection of images - Thesis

    OpenAIRE

    Stojanovic, Igor

    2011-01-01

    An algorithm for recognition and retrieval of image from image collection is developed. Basis of the algorithm is the progressive wavelet correlation. The final result is the recognition and retrieval of the wanted image, if it is in the image collection. Instructions for the choice of correlation threshold value for obtaining desired results are defined. The areas where the algorithm can be applied are also discussed. To increase efficiency is presented two phases solution. The first phase u...

  11. Image correlates of crowding in natural scenes.

    Science.gov (United States)

    Wallis, Thomas S A; Bex, Peter J

    2012-07-13

    Visual crowding is the inability to identify visible features when they are surrounded by other structure in the peripheral field. Since natural environments are replete with structure and most of our visual field is peripheral, crowding represents the primary limit on vision in the real world. However, little is known about the characteristics of crowding under natural conditions. Here we examine where crowding occurs in natural images. Observers were required to identify which of four locations contained a patch of "dead leaves'' (synthetic, naturalistic contour structure) embedded into natural images. Threshold size for the dead leaves patch scaled with eccentricity in a manner consistent with crowding. Reverse correlation at multiple scales was used to determine local image statistics that correlated with task performance. Stepwise model selection revealed that local RMS contrast and edge density at the site of the dead leaves patch were of primary importance in predicting the occurrence of crowding once patch size and eccentricity had been considered. The absolute magnitudes of the regression weights for RMS contrast at different spatial scales varied in a manner consistent with receptive field sizes measured in striate cortex of primate brains. Our results are consistent with crowding models that are based on spatial averaging of features in the early stages of the visual system, and allow the prediction of where crowding is likely to occur in natural images.

  12. Digital image processing applied Rock Art tracing

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    1998-06-01

    Full Text Available Adequate graphic recording has been one of the main objectives of rock art research. Photography has increased its role as a documentary technique. Now, digital image and its treatment allows new ways to observe the details of the figures and to develop a recording procedure which is as, or more, accurate than direct tracing. This technique also avoid deterioration of the rock paintings. The mathematical basis of this method is also presented.

    La correcta documentación del arte rupestre ha sido una preocupación constante por parte de los investigadores. En el desarrollo de nuevas técnicas de registro, directas e indirectas, la fotografía ha ido adquiriendo mayor protagonismo. La imagen digital y su tratamiento permiten nuevas posibilidades de observación de las figuras representadas y, en consecuencia, una lectura mediante la realización de calcos indirectos de tanta o mayor fiabilidad que la observación directa. Este sistema evita los riesgos de deterioro que provocan los calcos directos. Se incluyen las bases matemáticas que sustentan el método.

  13. Conical Fourier shell correlation applied to electron tomograms.

    Science.gov (United States)

    Diebolder, C A; Faas, F G A; Koster, A J; Koning, R I

    2015-05-01

    The resolution of electron tomograms is anisotropic due to geometrical constraints during data collection, such as the limited tilt range and single axis tilt series acquisition. Acquisition of dual axis tilt series can decrease these effects. However, in cryo-electron tomography, to limit the electron radiation damage that occurs during imaging, the total dose should not increase and must be fractionated over the two tilt series. Here we set out to determine whether it is beneficial fractionate electron dose for recording dual axis cryo electron tilt series or whether it is better to perform single axis acquisition. To assess the quality of tomographic reconstructions in different directions here we introduce conical Fourier shell correlation (cFSCe/o). Employing cFSCe/o, we compared the resolution isotropy of single-axis and dual-axis (cryo-)electron tomograms using even/odd split data sets. We show that the resolution of dual-axis simulated and cryo-electron tomograms in the plane orthogonal to the electron beam becomes more isotropic compared to single-axis tomograms and high resolution peaks along the tilt axis disappear. cFSCe/o also allowed us to compare different methods for the alignment of dual-axis tomograms. We show that different tomographic reconstruction programs produce different anisotropic resolution in dual axis tomograms. We anticipate that cFSCe/o can also be useful for comparisons of acquisition and reconstruction parameters, and different hardware implementations.

  14. Correlation network analysis applied to complex biofilm communities.

    Directory of Open Access Journals (Sweden)

    Ana E Duran-Pinedo

    Full Text Available The complexity of the human microbiome makes it difficult to reveal organizational principles of the community and even more challenging to generate testable hypotheses. It has been suggested that in the gut microbiome species such as Bacteroides thetaiotaomicron are keystone in maintaining the stability and functional adaptability of the microbial community. In this study, we investigate the interspecies associations in a complex microbial biofilm applying systems biology principles. Using correlation network analysis we identified bacterial modules that represent important microbial associations within the oral community. We used dental plaque as a model community because of its high diversity and the well known species-species interactions that are common in the oral biofilm. We analyzed samples from healthy individuals as well as from patients with periodontitis, a polymicrobial disease. Using results obtained by checkerboard hybridization on cultivable bacteria we identified modules that correlated well with microbial complexes previously described. Furthermore, we extended our analysis using the Human Oral Microbe Identification Microarray (HOMIM, which includes a large number of bacterial species, among them uncultivated organisms present in the mouth. Two distinct microbial communities appeared in healthy individuals while there was one major type in disease. Bacterial modules in all communities did not overlap, indicating that bacteria were able to effectively re-associate with new partners depending on the environmental conditions. We then identified hubs that could act as keystone species in the bacterial modules. Based on those results we then cultured a not-yet-cultivated microorganism, Tannerella sp. OT286 (clone BU063. After two rounds of enrichment by a selected helper (Prevotella oris OT311 we obtained colonies of Tannerella sp. OT286 growing on blood agar plates. This system-level approach would open the possibility of

  15. Applying Quaternion Fourier Transforms for Enhancing Color Images

    Directory of Open Access Journals (Sweden)

    M.I. Khalil

    2012-03-01

    Full Text Available The Fourier transforms play a critical role in a broad range of image processing applications, including enhancement, analysis, restoration, and compression. Until recently, it was common to use the conventional methods to deal with colored images. These methods are based on RGB decomposition of the colored image by separating it into three separate scalar images and computing the Fourier transforms of these images separately. The computing of the Hypercomplex 2D Fourier transform of a color image as a whole unit has only recently been realized. This paper is concerned with frequency domain noise reduction of color images using quaternion Fourier transforms. The approach is based on obtaining quaternion Fourier transform of the color image and applying the Gaussian filter to it in the frequency domain. The filtered image is then obtained by calculating the inverse quaternion Fourier transforms.

  16. Cell Matrix Remodeling Ability Shown by Image Spatial Correlation

    Directory of Open Access Journals (Sweden)

    Chi-Li Chiu

    2013-01-01

    Full Text Available Extracellular matrix (ECM remodeling is a critical step of many biological and pathological processes. However, most of the studies to date lack a quantitative method to measure ECM remodeling at a scale comparable to cell size. Here, we applied image spatial correlation to collagen second harmonic generation (SHG images to quantitatively evaluate the degree of collagen remodeling by cells. We propose a simple statistical method based on spatial correlation functions to determine the size of high collagen density area around cells. We applied our method to measure collagen remodeling by two breast cancer cell lines (MDA-MB-231 and MCF-7, which display different degrees of invasiveness, and a fibroblast cell line (NIH/3T3. We found distinct collagen compaction levels of these three cell lines by applying the spatial correlation method, indicating different collagen remodeling ability. Furthermore, we quantitatively measured the effect of Latrunculin B and Marimastat on MDA-MB-231 cell line collagen remodeling ability and showed that significant collagen compaction level decreases with these treatments.

  17. Study of size effect using digital image correlation

    Directory of Open Access Journals (Sweden)

    A. H. A. SANTOS

    Full Text Available Size effect is an important issue in concrete structures bearing in mind that it can influence many aspects of analysis such as strength, brittleness and structural ductility, fracture toughness and fracture energy, among others. Further this, ever more new methods are being developed to evaluate displacement fields in structures. In this paper an experimental evaluation of the size effect is performed applying Digital Image Correlation (DIC technique to measure displacements on the surface of beams. Three point bending tests were performed on three different size concrete beams with a notch at the midspan. The results allow a better understanding of the size effect and demonstrate the efficiency of Digital Image Correlation to obtain measures of displacements.

  18. Self-calibrated correlation imaging with k-space variant correlation functions.

    Science.gov (United States)

    Li, Yu; Edalati, Masoud; Du, Xingfu; Wang, Hui; Cao, Jie J

    2017-07-07

    Correlation imaging is a previously developed high-speed MRI framework that converts parallel imaging reconstruction into the estimate of correlation functions. The presented work aims to demonstrate this framework can provide a speed gain over parallel imaging by estimating k-space variant correlation functions. Because of Fourier encoding with gradients, outer k-space data contain higher spatial-frequency image components arising primarily from tissue boundaries. As a result of tissue-boundary sparsity in the human anatomy, neighboring k-space data correlation varies from the central to the outer k-space. By estimating k-space variant correlation functions with an iterative self-calibration method, correlation imaging can benefit from neighboring k-space data correlation associated with both coil sensitivity encoding and tissue-boundary sparsity, thereby providing a speed gain over parallel imaging that relies only on coil sensitivity encoding. This new approach is investigated in brain imaging and free-breathing neonatal cardiac imaging. Correlation imaging performs better than existing parallel imaging techniques in simulated brain imaging acceleration experiments. The higher speed enables real-time data acquisition for neonatal cardiac imaging in which physiological motion is fast and non-periodic. With k-space variant correlation functions, correlation imaging gives a higher speed than parallel imaging and offers the potential to image physiological motion in real-time. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Analysis of correlation coefficient filtering in elasticity imaging.

    Science.gov (United States)

    Huang, Sheng-Wen; Rubin, Jonathan M; Xie, Hua; Witte, Russell S; Jia, Congxian; Olafsson, Ragnar; O'Donnell, Matthew

    2008-11-01

    Correlation-based speckle tracking methods are commonly used in elasticity imaging to estimate displacements. In the presence of local strain, a larger window size results in larger displacement error. To reduce tracking error, we proposed a short correlation window followed by a correlation coefficient filter. Although simulation and experimental results demonstrated the efficacy of the method, it was not clear why correlation coefficient filtering reduces tracking error since tracking error increases if normalization before filtering is not applied. In this paper, we analyzed tracking errors by estimating phase variances of the cross-correlation function and the correlation coefficient at the true time lag based on statistical properties of these functions' real and imaginary parts. The role of normalization is clarified by identifying the effect of the cross-correlation function's amplitude fluctuation on the function's imaginary part. Furthermore, we present analytic forms for predicting axial displacement error as a function of strain, system parameters (signal-to-noise ratio, center frequency, and signal and noise bandwidths), and tracking parameters (window and filter sizes) for cases with and without normalization before filtering. Simulation results correspond to theory well for both noise-free cases and general cases with an empirical correction term included for strains up to 4%.

  20. Correlation of Magnetic Resonance Imaging Tumor Volume with Histopathology

    Science.gov (United States)

    Turkbey, Baris; Mani, Haresh; Aras, Omer; Rastinehad, Ardeshir R.; Shah, Vijay; Bernardo, Marcelino; Pohida, Thomas; Daar, Dagane; Benjamin, Compton; McKinney, Yolanda L.; Linehan, W. Marston; Wood, Bradford J.; Merino, Maria J.; Choyke, Peter L.; Pinto, Peter A.

    2017-01-01

    Purpose The biology of prostate cancer may be influenced by the index lesion. The definition of index lesion volume is important for appropriate decision making, especially for image guided focal treatment. We determined the accuracy of magnetic resonance imaging for determining index tumor volume compared with volumes derived from histopathology. Materials and Methods We evaluated 135 patients (mean age 59.3 years) with a mean prostate specific antigen of 6.74 ng/dl who underwent multiparametric 3T endorectal coil magnetic resonance imaging of the prostate and subsequent radical prostatectomy. Index tumor volume was determined prospectively and independently by magnetic resonance imaging and histopathology. The ellipsoid formula was applied to determine histopathology tumor volume, whereas manual tumor segmentation was used to determine magnetic resonance tumor volume. Histopathology tumor volume was correlated with age and prostate specific antigen whereas magnetic resonance tumor volume involved Pearson correlation and linear regression methods. In addition, the predictive power of magnetic resonance tumor volume, prostate specific antigen and age for estimating histopathology tumor volume (greater than 0.5 cm3) was assessed by ROC analysis. The same analysis was also conducted for the 1.15 shrinkage factor corrected histopathology data set. Results There was a positive correlation between histopathology tumor volume and magnetic resonance tumor volume (Pearson coefficient 0.633, p <0.0001), but a weak correlation between prostate specific antigen and histopathology tumor volume (Pearson coefficient 0.237, p=0.003). On linear regression analysis histopathology tumor volume and magnetic resonance tumor volume were correlated (r2=0.401, p <0.00001). On ROC analysis AUC values for magnetic resonance tumor volume, prostate specific antigen and age in estimating tumors larger than 0.5 cm3 at histopathology were 0.949 (p <0.0000001), 0.685 (p=0.001) and 0.627 (p=0

  1. Quantifying the reliability of image replication studies: the image intraclass correlation coefficient (I2C2).

    Science.gov (United States)

    Shou, H; Eloyan, A; Lee, S; Zipunnikov, V; Crainiceanu, A N; Nebel, N B; Caffo, B; Lindquist, M A; Crainiceanu, C M

    2013-12-01

    This article proposes the image intraclass correlation (I2C2) coefficient as a global measure of reliability for imaging studies. The I2C2 generalizes the classic intraclass correlation (ICC) coefficient to the case when the data of interest are images, thereby providing a measure that is both intuitive and convenient. Drawing a connection with classical measurement error models for replication experiments, the I2C2 can be computed quickly, even in high-dimensional imaging studies. A nonparametric bootstrap procedure is introduced to quantify the variability of the I2C2 estimator. Furthermore, a Monte Carlo permutation is utilized to test reproducibility versus a zero I2C2, representing complete lack of reproducibility. Methodologies are applied to three replication studies arising from different brain imaging modalities and settings: regional analysis of volumes in normalized space imaging for characterizing brain morphology, seed-voxel brain activation maps based on resting-state functional magnetic resonance imaging (fMRI), and fractional anisotropy in an area surrounding the corpus callosum via diffusion tensor imaging. Notably, resting-state fMRI brain activation maps are found to have low reliability, ranging from .2 to .4. Software and data are available to provide easy access to the proposed methods.

  2. Fractional Fourier Transform Applied to Digital Images Encryption

    Science.gov (United States)

    Vilardy, Juan M.; Torres, Cesar O.; Mattos, Lorenzo

    2008-04-01

    In the present paper a digital algorithm was developed to make phase encryption of digital indexed images to color using the fractional Fourier transform (the images in RGB are converted to indexed before to encrypt). The indexed images are represented by a matrix of M×N pixels (where M defines the height and N is the Width of the image) and a color map (it's a matrix of C×3 elements, where C indicates the colors number of the image and the number 3 indicates the three columns associated with the color components: Red, Green and Blue of each pixel of the matrix of M×N) associated to the matrix of pixels to suitably represent the color information of the image. The indexed image (matrix of M×N pixels) to encrypt is placed as the phase of a complex exponential, then is transformed three times and multiplied in intermediate steps by two random phase masks statistically independent thus to obtain the encrypted image, for decrypt the coding image the encryption procedure is applied in the inverse sense to the conjugated complex of the encrypted image, then is taken the negative of the phase of the resulting function of the decryption process and the original image is obtained this way that had been encrypted; For the color map equal procedure is applied in the encryption/decryption process described previously for the matrix of M×N pixels. In the implemented cryptographic algorithm five keys are used, constituted by three fractional orders and two random phase masks, all these keys are necessary for a correct decryption providing a dependability to the transference of images by means of the communications nets.

  3. Digital Image Correlation: Metrological Characterization in Mechanical Analysis

    Science.gov (United States)

    Petrella, Orsola; Signore, Davide; Caramuta, Pietro; Toscano, Cinzia; Ferraiuolo, Michele

    2017-04-01

    The Digital Image Correlation (DIC) is a newly developed optical technique that is spreading in all engineering sectors because it allows the non-destructive estimation of the entire surface deformation without any contact with the component under analysis. These characteristics make the DIC very appealing in all the cases the global deformation state is to be known without using strain gages, which are the most used measuring device. The DIC is applicable to any material subjected to distortion caused by either thermal or mechanical load, allowing to obtain high-definition mapping of displacements and deformations. That is why in the civil and the transportation industry, DIC is very useful for studying the behavior of metallic materials as well as of composite materials. DIC is also used in the medical field for the characterization of the local strain field of the vascular tissues surface subjected to uniaxial tensile loading. DIC can be carried out in the two dimension mode (2D DIC) if a single camera is used or in a three dimension mode (3D DIC) if two cameras are involved. Each point of the test surface framed by the cameras can be associated with a specific pixel of the image and the coordinates of each point are calculated knowing the relative distance between the two cameras together with their orientation. In both arrangements, when a component is subjected to a load, several images related to different deformation states can be are acquired through the cameras. A specific software analyzes the images via the mutual correlation between the reference image (obtained without any applied load) and those acquired during the deformation giving the relative displacements. In this paper, a Metrological Characterization of the Digital Image Correlation is performed on aluminum and composite targets both in static and dynamic loading conditions by comparison between DIC and strain gauges measures. In the static test, interesting results have been obtained thanks

  4. High-scale discontinuity detection applied to Landsat images

    Science.gov (United States)

    Jones, Katharine J.

    1999-03-01

    Landsat image data were produced from a multispectral scanner on Landsat satellites. Vegetation indices are based on the distinctive rise in the reflectance of green vegetation: a wavelength increase from visible red to reflective infrared caused by the selective absorption of red light by chlorophyll for photosynthesis. The spectral bandwidth of different Landsat crops are uniquely different and provide a basis for High Scale Discontinuity Detection. High Scale Discontinuity Detection applied to Landsat cross sections (1D signals) detects boundaries between urban areas and agricultural areas and different crops. These boundaries will be used to reconstruct an image based on boundaries. This approach might be usefully applied to IR images, laser remote sensing or any image where vegetation changes abruptly because of altitude or moisture.

  5. Synthetic Aperture Sequential Beamformation applied to medical imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-01-01

    Synthetic Aperture Sequential Beamforming (SASB) is applied to medical ultrasound imaging using a multi element convex array transducer. The main motivation for SASB is to apply synthetic aperture techniques without the need for storing RF-data for a number of elements and hereby devise a system...... with a reduced system complexity. Using a 192 element, 3.5 MHz, λ-pitch transducer, it is demonstrated using tissue-phantom and wire-phantom measurements, how the speckle size and the detail resolution is improved compared to conventional imaging....

  6. On Correlated-noise Analyses Applied To Exoplanet Light Curves

    CERN Document Server

    Cubillos, Patricio; Loredo, Thomas J; Lust, Nate B; Blecic, Jasmina; Stemm, Madison

    2016-01-01

    Time-correlated noise is a significant source of uncertainty when modeling exoplanet light-curve data. A correct assessment of correlated noise is fundamental to determine the true statistical significance of our findings. Here we review three of the most widely used correlated-noise estimators in the exoplanet field, the time-averaging, residual-permutation, and wavelet-likelihood methods. We argue that the residual-permutation method is unsound in estimating the uncertainty of parameter estimates. We thus recommend to refrain from this method altogether. We characterize the behavior of the time averaging's rms-vs.-bin-size curves at bin sizes similar to the total observation duration, which may lead to underestimated uncertainties. For the wavelet-likelihood method, we note errors in the published equations and provide a list of corrections. We further assess the performance of these techniques by injecting and retrieving eclipse signals into synthetic and real Spitzer light curves, analyzing the results in...

  7. Geometrical Correlation and Matching of 2d Image Shapes

    Science.gov (United States)

    Vizilter, Y. V.; Zheltov, S. Y.

    2012-07-01

    The problem of image correspondence measure selection for image comparison and matching is addressed. Many practical applications require image matching "just by shape" with no dependence on the concrete intensity or color values. Most popular technique for image shape comparison utilizes the mutual information measure based on probabilistic reasoning and information theory background. Another approach was proposed by Pytiev (so called "Pytiev morphology") based on geometrical and algebraic reasoning. In this framework images are considered as piecewise-constant 2D functions, tessellation of image frame by the set of non-intersected connected regions determines the "shape" of image and the projection of image onto the shape of other image is determined. Morphological image comparison is performed using the normalized morphological correlation coefficients. These coefficients estimate the closeness of one image to the shape of other image. Such image analysis technique can be characterized as an ""ntensity-to-geometry" matching. This paper generalizes the Pytiev morphological approach for obtaining the pure "geometry-to-geometry" matching techniques. The generalized intensity-geometrical correlation coefficient is proposed including the linear correlation coefficient and the square of Pytiev correlation coefficient as its partial cases. The morphological shape correlation coefficient is proposed based on the statistical averaging of images with the same shape. Centered morphological correlation coefficient is obtained under the condition of intensity centering of averaged images. Two types of symmetric geometrical normalized correlation coefficients are proposed for comparison of shape-tessellations. The technique for correlation and matching of shapes with ordered intensities is proposed with correlation measures invariant to monotonous intensity transformations. The quality of proposed geometrical correlation measures is experimentally estimated in the task of

  8. Using Data Mining to Teach Applied Statistics and Correlation

    Science.gov (United States)

    Hartnett, Jessica L.

    2016-01-01

    This article describes two class activities that introduce the concept of data mining and very basic data mining analyses. Assessment data suggest that students learned some of the conceptual basics of data mining, understood some of the ethical concerns related to the practice, and were able to perform correlations via the Statistical Package for…

  9. Fluorescence Correlation Spectroscopy Applied to Living Plant Cells

    NARCIS (Netherlands)

    Hink, M.A.

    2002-01-01

    Keywords: Fluorescence correlation spectroscopy, photon counting histogram, intracellular, plant, AtSERK1In order to survive organisms have to be capable to adjust theirselves to changes in the environment. Cells, the building blocks of an organism react to these

  10. Digital Image Correlation for Performance Monitoring.

    Energy Technology Data Exchange (ETDEWEB)

    Palaviccini, Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, Daniel Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herzberg, Michael [National Security Campus, Kansas City, MO (United States)

    2016-02-01

    Evaluating the health of a mechanism requires more than just a binary evaluation of whether an operation was completed. It requires analyzing more comprehensive, full-field data. Health monitoring is a process of nondestructively identifying characteristics that indicate the fitness of an engineered component. In order to monitor unit health in a production setting, an automated test system must be created to capture the motion of mechanism parts in a real-time and non-intrusive manner. One way to accomplish this is by using high-speed video (HSV) and Digital Image Correlation (DIC). In this approach, individual frames of the video are analyzed to track the motion of mechanism components. The derived performance metrics allow for state-of-health monitoring and improved fidelity of mechanism modeling. The results are in-situ state-of-health identification and performance prediction. This paper introduces basic concepts of this test method, and discusses two main themes: the use of laser marking to add fiducial patterns to mechanism components, and new software developed to track objects with complex shapes, even as they move behind obstructions. Finally, the implementation of these tests into an automated tester is discussed.

  11. Imaging in scattering media via the second-order correlation of light field

    CERN Document Server

    Gong, Wenlin; Shen, Xia; Han, Shensheng

    2009-01-01

    Imaging with the second-order correlation of two light fields is a method to image an object by two-photon interference involving a joint detection of two photons at distant space-time points. We demonstrate for the first time that an image with high quality can still be obtained in the scattering media by applying the second-order correlation of illuminating light field. The scattering effect on the visibility of images is analyzed both theoretically and experimentally. Potential applications and the methods to further improve the visibility of the images in scattering media are also discussed.

  12. Spatial Correlation Coefficient Images for Ultrasonic Detection (Preprint)

    Science.gov (United States)

    2006-07-01

    for image formation and detection based on the similarity of adjacent signals. Signal similarity is quantified in terms of the correlation coefficient calculated...between A-scans digitized at adjacent measurement positions. Correlation coefficient images are introduced for visualizing the similarity...beam field with the defect. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular

  13. Sub-Rayleigh limit imaging via intensity correlation measurements

    Institute of Scientific and Technical Information of China (English)

    姚旭日; 李龙珍; 刘雪峰; 俞文凯; 翟光杰

    2015-01-01

    We demonstrate sub-Rayleigh limit imaging of an object via intensity correlation measurements. The image com-pletely unaffected by the disturbance of diffraction-limit is achieved under the condition that the imaging system has an appropriate field of view. The resolution of this sub-Rayleigh limit imaging system is only tied to the lateral resolution of the illumination light.

  14. On Correlated-noise Analyses Applied to Exoplanet Light Curves

    Science.gov (United States)

    Cubillos, Patricio; Harrington, Joseph; Loredo, Thomas J.; Lust, Nate B.; Blecic, Jasmina; Stemm, Madison

    2017-01-01

    Time-correlated noise is a significant source of uncertainty when modeling exoplanet light-curve data. A correct assessment of correlated noise is fundamental to determine the true statistical significance of our findings. Here, we review three of the most widely used correlated-noise estimators in the exoplanet field, the time-averaging, residual-permutation, and wavelet-likelihood methods. We argue that the residual-permutation method is unsound in estimating the uncertainty of parameter estimates. We thus recommend to refrain from this method altogether. We characterize the behavior of the time averaging’s rms-versus-bin-size curves at bin sizes similar to the total observation duration, which may lead to underestimated uncertainties. For the wavelet-likelihood method, we note errors in the published equations and provide a list of corrections. We further assess the performance of these techniques by injecting and retrieving eclipse signals into synthetic and real Spitzer light curves, analyzing the results in terms of the relative-accuracy and coverage-fraction statistics. Both the time-averaging and wavelet-likelihood methods significantly improve the estimate of the eclipse depth over a white-noise analysis (a Markov-chain Monte Carlo exploration assuming uncorrelated noise). However, the corrections are not perfect when retrieving the eclipse depth from Spitzer data sets, these methods covered the true (injected) depth within the 68% credible region in only ˜45%-65% of the trials. Lastly, we present our open-source model-fitting tool, Multi-Core Markov-Chain Monte Carlo (MC3). This package uses Bayesian statistics to estimate the best-fitting values and the credible regions for the parameters for a (user-provided) model. MC3 is a Python/C code, available at https://github.com/pcubillos/MCcubed.

  15. Experimental analysis of image noise and interpolation bias in digital image correlation

    Science.gov (United States)

    Gao, Zeren; Xu, Xiaohai; Su, Yong; Zhang, Qingchuan

    2016-06-01

    The popularization of the digital image correlation (DIC) method has raised urgent needs to evaluate the accuracy of this method. However, there are still some problems to be solved. Among the problems, the effects of various factors, such as the image noise caused by the camera sensors, the employed interpolation algorithm, and the structure of the speckle patterns, have become a major concern. To experimentally measure the position-dependent systematic error (i.e. interpolation bias) caused by non-ideal interpolation algorithm is an important way to evaluate the quality of the speckle patterns in the correlation method, and remains unsolved. In this work, a novel, simple and convenient method is proposed to measure the interpolation bias. In the new method which can avoid the out-of-plane displacements and the mechanical errors of translation stages, integral-pixel shifts are applied to the image shown on the screen so that sub-pixel displacements can be realized in the images captured by the camera via proper experimental settings. Besides, the fluctuations of the image noise and the sub-pixel displacement errors caused by the image noise are experimentally analyzed by employing three types of cameras commonly used in the DIC measurements. Experimental results indicate that the fluctuations of the image noise are not only proportional to the image gray value, but also dependent on the type of the employed camera. On the basis of eliminating the image noise via the image averaging technique, high-precision interpolation bias curves more than one period are experimentally obtained by the proposed method.

  16. Heavy-Ion <span class="hlt">Imaging</span> <span class="hlt">Applied</span> To Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J. I.; Tobias, C. A.; Capp, M. P.; Benton, E. V.; Holley, W. R.; Gray, Joel E.; Hendee, William R.; Haus, Andrew G.; Properzio, William S.

    1980-08-18

    Heavy particle radiography is a newly developed noninvasive low dose imaging procedure with increased resolution of minute density differences in soft tissues of the body. The method utilizes accelerated high energy ions, primarily carbon and neon, at the BEVALAC accelerator at the Lawrence Berkeley Laboratory. The research program applied to medicine utilizes heavy-ion radiography for low dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures and brain and spinal neoplasms. The presentation will be illustrated with clinical cases under study. Discussion will include the potential of heavy-ion imaging, and particularly reconstruction tomography, as an adjunct to existing diagnostic imaging procedures in medicine, both for the applications to the diagnosis, management and treatment of clinical cancer in man, but also for the early detection of small soft tissue tumors at low radiation dose.

  17. Applied TICs in Education and its correlation in Academic Performance

    Directory of Open Access Journals (Sweden)

    Jenny Maritza Rosero Lozano

    2016-08-01

    Full Text Available In the present study, we want to determinate the correlation between educational TICS application and the academic effiency in the subject of programmation in Structured languages which lasted 10 months and It was developed with 5 educators, 73 legal representatives and 103 students who belong to the services Technician bachelor, speciality in Informatic applications. It is based in the Constructivism by Jean Piaget, in the techniques focused in the personalized teaching in the significant learning theory by D´ıaz Barriga. The correlation coefficient by Pearson was used for measuring the different variables. The results revealed the low academic effiency of the students in the subject. It motivated the development of a propose which was a ”WEBQUEST”designed in Exelearning that allows to create learning materials which combine text with multimedia elements and It does not require internet to execute the functions with the purpose of facilitating the student body development in its abilities, capacities and skills, the educator can use it as a didatic strategy because It helps to keep an active and creative participation of the students and It allows to the users to acquire knowledge and skills in the computer programms creation. The software was tested and validated by the educational community, It has as a result a big acceptance, good perspectives in its use and the improvement in the students academic effiency.

  18. Practical approach to apply range image sensors in machine automation

    Science.gov (United States)

    Moring, Ilkka; Paakkari, Jussi

    1993-10-01

    In this paper we propose a practical approach to apply range imaging technology in machine automation. The applications we are especially interested in are industrial heavy-duty machines like paper roll manipulators in harbor terminals, harvesters in forests and drilling machines in mines. Characteristic of these applications is that the sensing system has to be fast, mid-ranging, compact, robust, and relatively cheap. On the other hand the sensing system is not required to be generic with respect to the complexity of scenes and objects or number of object classes. The key in our approach is that just a limited range data set or as we call it, a sparse range image is acquired and analyzed. This makes both the range image sensor and the range image analysis process more feasible and attractive. We believe that this is the way in which range imaging technology will enter the large industrial machine automation market. In the paper we analyze as a case example one of the applications mentioned and, based on that, we try to roughly specify the requirements for a range imaging based sensing system. The possibilities to implement the specified system are analyzed based on our own work on range image acquisition and interpretation.

  19. Magnetic Resonance Imaging of Cerebral Aspergillosis: Imaging and Pathological Correlations

    Science.gov (United States)

    Sabou, Marcela; Lannes, Béatrice; Cotton, François; Meyronet, David; Galanaud, Damien; Cottier, Jean-Philippe; Grand, Sylvie; Desal, Hubert; Kreutz, Julie; Schenck, Maleka; Meyer, Nicolas; Schneider, Francis; Dietemann, Jean-Louis; Koob, Meriam

    2016-01-01

    Cerebral aspergillosis is associated with a significant morbidity and mortality rate. The imaging data present different patterns and no full consensus exists on typical imaging characteristics of the cerebral lesions. We reviewed MRI findings in 21 patients with cerebral aspergillosis and correlated them to the immune status of the patients and to neuropathological findings when tissue was available. The lesions were characterized by their number, topography, and MRI signal. Dissemination to the brain resulted from direct spread from paranasal sinuses in 8 patients, 6 of them being immunocompetent. Hematogenous dissemination was observed in 13 patients, all were immunosuppressed. In this later group we identified a total of 329 parenchymal abscesses involving the whole brain with a predilection for the corticomedullary junction. More than half the patients had a corpus callosum lesion. Hemorrhagic lesions accounted for 13% and contrast enhancement was observed in 61% of the lesions. Patients with hematogenous dissemination were younger (p = 0.003), had more intracranial lesions (p = 0.0004) and had a higher 12-week mortality rate (p = 0.046) than patients with direct spread from paranasal sinuses. Analysis of 12 aneurysms allowed us to highlight two distinct situations. In case of direct spread from the paranasal sinuses, aneurysms are saccular and located on the proximal artery portions, while the hematogenous dissemination in immunocompromised patients is more frequently associated with distal and fusiform aneurysms. MRI is the exam of choice for cerebral aspergillosis. Number and type of lesions are different according to the mode of dissemination of the infection. PMID:27097323

  20. A study of correlation technique on pyramid processed images

    Indian Academy of Sciences (India)

    M Sankar Kishore; K Veerabhadra Rao

    2000-02-01

    The pyramid algorithm is potentially a powerful tool for advanced television image processing and for pattern recognition. An attempt is made to design and develop both hardware and software for a system which performs decomposition and reconstruction of digitized images by implementing the Burt pyramid algorithm. In this work, an attempt is also made to study correlation performance on reconstructed images. That is, the reference image is taken from the original image and correlation is performed on expanded images of the same size. Similarly, correlation performance study is carried out on different pyramid- processed levels. In this paper results are presented in terms of RMS error between original and expanded images. Only still images are considered, and the hardware is designed around an i486 processor and software is developed in PL/M 86.

  1. Image-Based Learning Approach Applied to Time Series Forecasting

    Directory of Open Access Journals (Sweden)

    J. C. Chimal-Eguía

    2012-06-01

    Full Text Available In this paper, a new learning approach based on time-series image information is presented. In order to implementthis new learning technique, a novel time-series input data representation is also defined. This input datarepresentation is based on information obtained by image axis division into boxes. The difference between this newinput data representation and the classical is that this technique is not time-dependent. This new information isimplemented in the new Image-Based Learning Approach (IBLA and by means of a probabilistic mechanism thislearning technique is applied to the interesting problem of time series forecasting. The experimental results indicatethat by using the methodology proposed in this article, it is possible to obtain better results than with the classicaltechniques such as artificial neuronal networks and support vector machines.

  2. Correlation of proton MR spectroscopy and diffusion tensor imaging.

    Science.gov (United States)

    Irwan, Roy; Sijens, Paul E; Potze, Jan-Hendrik; Oudkerk, Matthijs

    2005-10-01

    Proton magnetic resonance spectroscopy ((1)H-MRS) provides indices of neuronal damage. Diffusion tensor imaging (DTI) relates to water diffusivity and fiber tract orientation. A method to compare (1)H-MRS and DTI findings was developed, tested on phantom and applied on normal brain. Point-resolved spectroscopy (T(R)/T(E)=1500/135) was used for chemical shift imaging of a supraventricular volume of interest of 8 x 8 x 2 cm(3) (64 voxels). In DTI, a segmental spin-echo sequence (T(R)/T(E)=5500/91) was used and slices were stacked to reproduce the slab used in MRS. The spatial distributions of choline and N-acetylaspartate (NAA) correlated to mean fractional anisotropy and apparent diffusion coefficient (ADC) for the inner 6 x 6=36 voxels defined in MRS, most notably NAA and ADC value (r=-.70, P<.00001; correlation across four subjects, 144 data pairs). This is the first association of neuron metabolite contents in volunteers with structure as indicated by DTI.

  3. Multimodal tissue perfusion imaging using multi-spectral and thermographic imaging systems applied on clinical data

    Science.gov (United States)

    Klaessens, John H. G. M.; Nelisse, Martin; Verdaasdonk, Rudolf M.; Noordmans, Herke Jan

    2013-03-01

    Clinical interventions can cause changes in tissue perfusion, oxygenation or temperature. Real-time imaging of these phenomena could be useful for surgical strategy or understanding of physiological regulation mechanisms. Two noncontact imaging techniques were applied for imaging of large tissue areas: LED based multispectral imaging (MSI, 17 different wavelengths 370 nm-880 nm) and thermal imaging (7.5 to 13.5 μm). Oxygenation concentration changes were calculated using different analyzing methods. The advantages of these methods are presented for stationary and dynamic applications. Concentration calculations of chromophores in tissue require right choices of wavelengths The effects of different wavelength choices for hemoglobin concentration calculations were studied in laboratory conditions and consequently applied in clinical studies. Corrections for interferences during the clinical registrations (ambient light fluctuations, tissue movements) were performed. The wavelength dependency of the algorithms were studied and wavelength sets with the best results will be presented. The multispectral and thermal imaging systems were applied during clinical intervention studies: reperfusion of tissue flap transplantation (ENT), effectiveness of local anesthetic block and during open brain surgery in patients with epileptic seizures. The LED multispectral imaging system successfully imaged the perfusion and oxygenation changes during clinical interventions. The thermal images show local heat distributions over tissue areas as a result of changes in tissue perfusion. Multispectral imaging and thermal imaging provide complementary information and are promising techniques for real-time diagnostics of physiological processes in medicine.

  4. Characterization of SEM speckle pattern marking and imaging distortion by Digital Image Correlation

    OpenAIRE

    Guery, Adrien; Latourte, Felix; Hild, François; Roux, Stéphane

    2014-01-01

    International audience; Surface patterning by e-beam lithography and SEM imaging distortions are studied via digital image correlation. The global distortions from the reference pattern, which has been numerically generated, are first quantified from a digital image correlation procedure between the (virtual) reference pattern and the actual SEM image both in secondary and backscattered electron imaging modes. These distortions result from both patterning and imaging techniques. These two con...

  5. Quality assessment of butter cookies applying multispectral imaging

    Science.gov (United States)

    Andresen, Mette S; Dissing, Bjørn S; Løje, Hanne

    2013-01-01

    A method for characterization of butter cookie quality by assessing the surface browning and water content using multispectral images is presented. Based on evaluations of the browning of butter cookies, cookies were manually divided into groups. From this categorization, reference values were calculated for a statistical prediction model correlating multispectral images with a browning score. The browning score is calculated as a function of oven temperature and baking time. It is presented as a quadratic response surface. The investigated process window was the intervals 4–16 min and 160–200°C in a forced convection electrically heated oven. In addition to the browning score, a model for predicting the average water content based on the same images is presented. This shows how multispectral images of butter cookies may be used for the assessment of different quality parameters. Statistical analysis showed that the most significant wavelengths for browning predictions were in the interval 400–700 nm and the wavelengths significant for water prediction were primarily located in the near-infrared spectrum. The water prediction model was found to correctly estimate the average water content with an absolute error of 0.22%. From the images it was also possible to follow the browning and drying propagation from the cookie edge toward the center. PMID:24804036

  6. Algorithm for image fusion via gradient correlation and difference statistics

    Science.gov (United States)

    Han, Jing; Wang, Li-juan; Zhang, Yi; Bai, Lian-fa; Mao, Ningjie

    2016-10-01

    In order to overcome the shortcoming of traditional image fusion based on discrete wavelet transform (DWT), a novel image fusion algorithm based on gradient correlation and difference statistics is proposed in this paper. The source images are decomposed into low-frequency coefficients and high-frequency coefficients by DWT: the former are fused by a local gradient correlation based scheme to extract the local feature information in source images; the latter are fused by a neighbor difference statistics based scheme to reserve the conspicuous edge information. Finally, the fused image is reconstructed by inverse DWT. Experimental results show that the proposed method performs better than other methods in reserving details.

  7. Compressive optical image watermarking using joint Fresnel transform correlator architecture

    Science.gov (United States)

    Li, Jun; Zhong, Ting; Dai, Xiaofang; Yang, Chanxia; Li, Rong; Tang, Zhilie

    2017-02-01

    A new optical image watermarking technique based on compressive sensing using joint Fresnel transform correlator architecture has been presented. A secret scene or image is first embedded into a host image to perform optical image watermarking by use of joint Fresnel transform correlator architecture. Then, the watermarked image is compressed to much smaller signal data using single-pixel compressive holographic imaging in optical domain. At the received terminal, the watermarked image is reconstructed well via compressive sensing theory and a specified holographic reconstruction algorithm. The preliminary numerical simulations show that it is effective and suitable for optical image security transmission in the coming absolutely optical network for the reason of the completely optical implementation and largely decreased holograms data volume.

  8. Improved PCA + LDA Applies to Gastric Cancer Image Classification Process

    Science.gov (United States)

    Gan, Lan; Lv, Wenya; Zhang, Xu; Meng, Xiuming

    Principal component analysis (PCA) and linear discriminant analysis (LDA) are two most widely used pattern recognition methods in the field of feature extraction,while PCA + LDA is often used in image recognition.Here,we apply PCA + LDA to gastric cancer image feature classification, but the traditional PCA + LDA dimension reduction method has good effect on the training sample dimensionality and clustering, the effect on test samples dimension reduction and clustering is very poor, that is, the traditional PCA + LDA exists Generalization problem on the test samples. To solve this problem, this paper proposes an improved PCA + LDA method, which mainly considers from the LDA transform; improves the traditional PCA + LDA;increase the generalization performance of LDA on test samples and increases the classification accuracy on test samples. The experiment proves that the method can achieve good clustering.

  9. Application of the progressive wavelet correlation for image recognition and retrieval from the collection of images

    OpenAIRE

    Stojanovic, Igor; Markovski, Smile; Martinovska, Cveta; Mileva, Aleksandra

    2012-01-01

    An algorithm for recognition and retrieval of image from image collection is developed. Basis of the algorithm is the progressive wavelet correlation. The final result is the recognition and retrieval of the wanted image, if it is in the image collection. Instructions for the choice of correlation threshold value for obtaining desired results are defined. To increase efficiency is presented two phases solution. The first phase uses well known methods of image retrieving by descriptors based o...

  10. Confocal laser scanning microscopy image correlation for nanoparticle flow velocimetry

    CERN Document Server

    Jun, Brian; Yang, Haisheng; Main, Russell; Vlachos, Pavlos

    2016-01-01

    We present a new particle image correlation technique for resolving nanoparticle flow velocity using confocal laser scanning microscopy (CLSM). The two primary issues that complicate nanoparticle scanning laser image correlation (SLIC) based velocimetry are (1) the use of diffusion dominated nanoparticles as flow tracers, which introduce a random decorrelating error into the velocity estimate, and (2) the effects of the scanning laser image acquisition, which introduces a bias error. To date, no study has quantified these errors or demonstrated a means to deal with them in SLIC velocimetry. In this work, we build upon the robust phase correlation (RPC) and existing methods of SLIC to quantify and mitigate these errors. First, we implement an ensemble RPC instead of using an ensemble standard cross correlation, and develop an SLIC optimal filter that maximizes the correlation strength in order to reliably and accurately detect the correlation peak representing the most probable average displacement of the nano...

  11. Exploring underwater target detection by imaging polarimetry and correlation techniques.

    Science.gov (United States)

    Dubreuil, M; Delrot, P; Leonard, I; Alfalou, A; Brosseau, C; Dogariu, A

    2013-02-10

    Underwater target detection is investigated by combining active polarization imaging and optical correlation-based approaches. Experiments were conducted in a glass tank filled with tap water with diluted milk or seawater and containing targets of arbitrary polarimetric responses. We found that target estimation obtained by imaging with two orthogonal polarization states always improves detection performances when correlation is used as detection criterion. This experimental study illustrates the potential of polarization imaging for underwater target detection and opens interesting perspectives for the development of underwater imaging systems.

  12. Correlation image velocimetry: a spectral approach

    Science.gov (United States)

    Roux, Stéphane; Hild, François; Berthaud, Yves

    2002-01-01

    A method, believed to be new, is introduced to evaluate displacement fields from the analysis of a deformed image compared with a reference image. In contrast to standard methods, which determine a piecewise constant displacement field, the present method gives direct access to spectral decomposition of the displacement field. A minimization procedure is derived and used twice: first, to determine an affine displacement field and, then, the spectral components of the residual displacement. Although the method is applicable to any space dimension, only cases dealing with one-dimensional signals are reported: First, a purely synthetic example is discussed to estimate the intrinsic performance of the method, and a second case deals with a profile extracted from a sample of compressed glass wool.

  13. Hyperspectral imaging applied to complex particulate solids systems

    Science.gov (United States)

    Bonifazi, Giuseppe; Serranti, Silvia

    2008-04-01

    HyperSpectral Imaging (HSI) is based on the utilization of an integrated hardware and software (HW&SW) platform embedding conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Although HSI was originally developed for remote sensing, it has recently emerged as a powerful process analytical tool, for non-destructive analysis, in many research and industrial sectors. The possibility to apply on-line HSI based techniques in order to identify and quantify specific particulate solid systems characteristics is presented and critically evaluated. The originally developed HSI based logics can be profitably applied in order to develop fast, reliable and lowcost strategies for: i) quality control of particulate products that must comply with specific chemical, physical and biological constraints, ii) performance evaluation of manufacturing strategies related to processing chains and/or realtime tuning of operative variables and iii) classification-sorting actions addressed to recognize and separate different particulate solid products. Case studies, related to recent advances in the application of HSI to different industrial sectors, as agriculture, food, pharmaceuticals, solid waste handling and recycling, etc. and addressed to specific goals as contaminant detection, defect identification, constituent analysis and quality evaluation are described, according to authors' originally developed application.

  14. correlation of magnetic resonance imaging findings with arthroscopy ...

    African Journals Online (AJOL)

    clinically diagnosed rotator cuff disease based upon the radiologist's interpretation with actual intra- operative arthroscopic ... invasively display high definition anatomy images ... surgical correlation (4) enough to guide on the treatment ..... Sex. Pearson. Correlation. 0.251. -0.182. -0.182. 0.156. -0.289. 0.061. 0.156. -0.052.

  15. Neural network method applied to particle image velocimetry

    Science.gov (United States)

    Grant, Ian; Pan, X.

    1993-12-01

    realised. An important class of neural network is the multi-layer perceptron. The neurons are distributed on surfaces and linked by weighted interconnections. In the present paper we demonstrate how this type of net can developed into a competitive, adaptive filter which will identify PIV image pairs in a number of commonly occurring flow types. Previous work by the authors in particle tracking analysis (1, 2) has shown the efficiency of statistical windowing techniques in flows without systematic (in time or space) variations. The effectiveness of the present neural net is illustrated by applying it to digital simulations ofturbulent and rotating flows. Work reported by Cenedese et al (3) has taken a different approach in examining the potential for neural net methods applied to PIV.

  16. Multi-modal registration for correlative microscopy using image analogies.

    Science.gov (United States)

    Cao, Tian; Zach, Christopher; Modla, Shannon; Powell, Debbie; Czymmek, Kirk; Niethammer, Marc

    2014-08-01

    Correlative microscopy is a methodology combining the functionality of light microscopy with the high resolution of electron microscopy and other microscopy technologies for the same biological specimen. In this paper, we propose an image registration method for correlative microscopy, which is challenging due to the distinct appearance of biological structures when imaged with different modalities. Our method is based on image analogies and allows to transform images of a given modality into the appearance-space of another modality. Hence, the registration between two different types of microscopy images can be transformed to a mono-modality image registration. We use a sparse representation model to obtain image analogies. The method makes use of corresponding image training patches of two different imaging modalities to learn a dictionary capturing appearance relations. We test our approach on backscattered electron (BSE) scanning electron microscopy (SEM)/confocal and transmission electron microscopy (TEM)/confocal images. We perform rigid, affine, and deformable registration via B-splines and show improvements over direct registration using both mutual information and sum of squared differences similarity measures to account for differences in image appearance. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Cholangiocarcinoma: Correlation between Molecular Profiling and Imaging Phenotypes.

    Directory of Open Access Journals (Sweden)

    Eran Sadot

    Full Text Available To investigate associations between imaging features of cholangiocarcinoma by visual assessment and texture analysis, which quantifies heterogeneity in tumor enhancement patterns, with molecular profiles based on hypoxia markers.The institutional review board approved this HIPAA-compliant retrospective study of CT images of intrahepatic cholangiocarcinoma, obtained before surgery. Immunostaining for hypoxia markers (EGFR, VEGF, CD24, P53, MDM2, MRP-1, HIF-1α, CA-IX, and GLUT1 was performed on pre-treatment liver biopsies. Quantitative imaging phenotypes were determined by texture analysis with gray level co-occurrence matrixes. The correlations between quantitative imaging phenotypes, qualitative imaging features (measured by radiographic inspection alone, and expression levels of the hypoxia markers from the 25 tumors were assessed.Twenty-five patients were included with a median age of 62 years (range: 54-84. The median tumor size was 10.2 cm (range: 4-14, 10 (40% were single tumors, and 90% were moderately differentiated. Positive immunostaining was recorded for VEGF in 67% of the cases, EGFR in 75%, and CD24 in 55%. On multiple linear regression analysis, quantitative imaging phenotypes correlated significantly with EGFR and VEGF expression levels (R2 = 0.4, p<0.05 and R2 = 0.2, p<0.05, respectively, while a trend was demonstrated with CD24 expression (R2 = 0.33, p = 0.1. Three qualitative imaging features correlated with VEGF and CD24 expression (P<0.05, however, none of the qualitative features correlated with the quantitative imaging phenotypes.Quantitative imaging phenotypes, as defined by texture analysis, correlated with expression of specific markers of hypoxia, regardless of conventional imaging features.

  18. Visualization of biological texture using correlation coefficient images.

    Science.gov (United States)

    Sviridov, Alexander P; Ulissi, Zachary; Chernomordik, Victor; Hassan, Moinuddin; Gandjbakhche, Amir H

    2006-01-01

    Subsurface structural features of biological tissue are visualized using polarized light images. The technique of Pearson correlation coefficient analysis is used to reduce blurring of these features by unpolarized backscattered light and to visualize the regions of high statistical similarities within the noisy tissue images. It is shown that under certain conditions, such correlation coefficient maps are determined by the textural character of tissues and not by the chosen region of interest, providing information on tissue structure. As an example, the subsurface texture of a demineralized tooth sample is enhanced from a noisy polarized light image.

  19. Image processing applied to measurement of particle size

    Science.gov (United States)

    Vega, Fabio; Lasso, Willian; Torres, Cesar

    2015-01-01

    Five different types of aggregates have been analyzed, and the size of particles on samples immersed in distilled water as silicon dioxide, titanium dioxide, styrenes and crushed silica particles is made; an attempt at applying the digital image processing (DIP) technique to analyze the particle size, we developed a system of measures microparticles using a microscope, a CCD camera and acquisition software and video processing developed in MATLAB. These studies are combined with laser light using measurements by diffractometry and obtain calibration in the system implemented, in this work we achievement measurement particle size on the order of 4 to 6 micrometers. The study demonstrates that DIP is a fast, convenient, versatile, and accurate technique for particle size analysis; the limitations of implemented setup too will be discussed.

  20. Application of digital-image-correlation techniques in analysing cracked cylindrical pipes

    Indian Academy of Sciences (India)

    Shih-Heng Tung; Chung-Huan Sui

    2010-10-01

    Cracks induced by external excitation on a material that has defects may generate the stress concentration phenomenon. The stress concentration behaviour causes local buckling, which will induce the damage of the members made of this material. Thus, developing techniques to monitor the strain variation of a cracked member is an important study. The traditional technique (such as strain gauge) can only measure the average strain of a region. The strain variation within this region cannot be determined. Therefore, it cannot sufficiently reflect the mechanical behaviour surrounding the crack. The Digital image correlation technique recently developed is an image identification technique to be applied for measuring the object deformation. This technique is capable of correlating the digital images of an object before and after deformation and further determining the displacement and strain field of an object based on the corresponding position on the image. In this work, this technique is applied to analyse the mechanics of a cylindrical pipe experiencing crack destruction. The fixing device is used to avoid shaking the specimen during the pressurizing process. The image capture instruments are fixed on the stable frame to measure the deformation of specimen accurately. Through the cylindrical pipe cracking test, the capacity of the digital image correlation technique for surveying the strain variation in a tiny region is validated. Then, the experimental results obtained using the digital image correlation analysis is used to demonstrate the crack development tendency in defect materials and the stress concentration zone.

  1. Quantum Multi-Image Encryption Based on Iteration Arnold Transform with Parameters and Image Correlation Decomposition

    Science.gov (United States)

    Hu, Yiqun; Xie, Xinwen; Liu, Xingbin; Zhou, Nanrun

    2017-07-01

    A novel quantum multi-image encryption algorithm based on iteration Arnold transform with parameters and image correlation decomposition is proposed, and a quantum realization of the iteration Arnold transform with parameters is designed. The corresponding low frequency images are obtained by performing 2-D discrete wavelet transform on each image respectively, and then the corresponding low frequency images are spliced randomly to one image. The new image is scrambled by the iteration Arnold transform with parameters, and the gray-level information of the scrambled image is encoded by quantum image correlation decomposition. For the encryption algorithm, the keys are iterative times, added parameters, classical binary and orthonormal basis states. The key space, the security and the computational complexity are analyzed, and all of the analyses show that the proposed encryption algorithm could encrypt multiple images simultaneously with lower computational complexity compared with its classical counterparts.

  2. Traffic Sign Recognition System based on Cambridge Correlator Image Comparator

    Directory of Open Access Journals (Sweden)

    J. Turan

    2012-06-01

    Full Text Available Paper presents basic information about application of Optical Correlator (OC, specifically Cambridge Correlator, in system to recognize of traffic sign. Traffic Sign Recognition System consists of three main blocks, Preprocessing, Optical Correlator and Traffic Sign Identification. The Region of Interest (ROI is defined and chosen in preprocessing block and then goes to Optical Correlator, where is compared with database of Traffic Sign. Output of Optical Correlation is correlation plane, which consist of highly localized intensities, know as correlation peaks. The intensity of spots provides a measure of similarity and position of spots, how images (traffic signs are relatively aligned in the input scene. Several experiments have been done with proposed system and results and conclusion are discussed.

  3. A combined method for correlative 3D imaging of biological samples from macro to nano scale

    Science.gov (United States)

    Kellner, Manuela; Heidrich, Marko; Lorbeer, Raoul-Amadeus; Antonopoulos, Georgios C.; Knudsen, Lars; Wrede, Christoph; Izykowski, Nicole; Grothausmann, Roman; Jonigk, Danny; Ochs, Matthias; Ripken, Tammo; Kühnel, Mark P.; Meyer, Heiko

    2016-10-01

    Correlative analysis requires examination of a specimen from macro to nano scale as well as applicability of analytical methods ranging from morphological to molecular. Accomplishing this with one and the same sample is laborious at best, due to deformation and biodegradation during measurements or intermediary preparation steps. Furthermore, data alignment using differing imaging techniques turns out to be a complex task, which considerably complicates the interconnection of results. We present correlative imaging of the accessory rat lung lobe by combining a modified Scanning Laser Optical Tomography (SLOT) setup with a specially developed sample preparation method (CRISTAL). CRISTAL is a resin-based embedding method that optically clears the specimen while allowing sectioning and preventing degradation. We applied and correlated SLOT with Multi Photon Microscopy, histological and immunofluorescence analysis as well as Transmission Electron Microscopy, all in the same sample. Thus, combining CRISTAL with SLOT enables the correlative utilization of a vast variety of imaging techniques.

  4. Atlas-based diffusion tensor imaging correlates of executive function

    Science.gov (United States)

    Nowrangi, Milap A.; Okonkwo, Ozioma; Lyketsos, Constantine; Oishi, Kenichi; Mori, Susumu; Albert, Marilyn; Mielke, Michelle M.

    2015-01-01

    Impairment in executive function (EF) is commonly found in Alzheimer’s Dementia (AD) and Mild Cognitive Impairment (MCI). Atlas-based Diffusion Tensor Imaging (DTI) methods may be useful in relating regional integrity to EF measures in MCI and AD. 66 participants (25 NC, 22 MCI, and 19 AD) received DTI scans and clinical evaluation. DTI scans were applied to a pre-segmented atlas and fractional anisotropy (FA) and mean diffusivity (MD) were calculated. ANOVA was used to assess group differences in frontal, parietal, and cerebellar regions. For regions differing between groups (p<0.01), linear regression examined the relationship between EF scores and regional FA and MD. Anisotropy and diffusivity in frontal and parietal lobe white matter (WM) structures were associated with EF scores in MCI and only frontal lobe structures in AD. EF was more strongly associated with FA than MD. The relationship between EF and anisotropy and diffusivity was strongest in MCI. These results suggest that regional WM integrity is compromised in MCI and AD and that FA may be a better correlate of EF than MD. PMID:25318544

  5. Fast correlation technique for glacier flow monitoring by digital camera and space-borne SAR images

    Directory of Open Access Journals (Sweden)

    Moreau Luc

    2011-01-01

    Full Text Available Abstract Most of the image processing techniques have been first proposed and developed on small size images and progressively applied to larger and larger data sets resulting from new sensors and application requirements. In geosciences, digital cameras and remote sensing images can be used to monitor glaciers and to measure their surface velocity by different techniques. However, the image size and the number of acquisitions to be processed to analyze time series become a critical issue to derive displacement fields by the conventional correlation technique. In this paper, a mathematical optimization of the classical normalized cross-correlation and its implementation are described to overcome the computation time and window size limitations. The proposed implementation is performed with a specific memory management to avoid most of the temporary result re-computations. The performances of the software resulting from this optimization are assessed by computing the correlation between optical images of a serac fall, and between Synthetic Aperture Radar (SAR images of Alpine glaciers. The optical images are acquired by a digital camera installed near the Argentière glacier (Chamonix, France and the SAR images are acquired by the high resolution TerraSAR-X satellite over the Mont-Blanc area. The results illustrate the potential of this implementation to derive dense displacement fields with a computational time compatible with the camera images acquired every 2 h and with the size of the TerraSAR-X scenes covering 30 × 50 km2.

  6. An edge-adaptive demosaicking method based on image correlation

    Institute of Scientific and Technical Information of China (English)

    贾晓芬; 赵佰亭; 周孟然; 陈兆权

    2015-01-01

    To reduce the cost, size and complexity, a consumer digital camera usually uses a single sensor overlaid with a color filter array (CFA) to sample one of the red−green−blue primary color values, and uses demosaicking algorithm to estimate the missing color values at each pixel. A novel image correlation and support vector machine (SVM) based edge-adaptive algorithm was proposed, which can reduce edge artifacts and false color artifacts, effectively. Firstly, image pixels were separated into edge region and smooth region with an edge detection algorithm. Then, a hybrid approach switching between a simple demosaicking algorithm on the smooth region and SVM based demosaicking algorithm on the edge region was performed. Image spatial and spectral correlations were employed to create middle planes for the interpolation. Experimental result shows that the proposed approach produced visually pleasing full-color result images and obtained higher CPSNR and smaller S-CIELAB *abDE than other conventional demosaicking algorithms.

  7. Shape determination of unidimensional objects: the virtual image correlation method

    Directory of Open Access Journals (Sweden)

    Auradou H.

    2010-06-01

    Full Text Available The proposed method, named Virtual Image Correlation, allows one to identify an analytical expression of the shape of a curvilinear object from its image. It uses a virtual beam, whose curvature field is expressed as a truncated mathematical series. The virtual beam width only needs to be close to the physical one; its gray level (in the transverse direction is bell-shaped. The method consists in finding the coefficients of the series for which the correlation between physical and virtual beams is the best. The accuracy and the robustness of the method is shown by the mean of two examples. The first details a Young’s modulus identification from a cantilever beam image. The second is relative to a thermal plume image, that have a weak contrast and a lot of noise.

  8. Shape determination of unidimensional objects: the virtual image correlation method

    Science.gov (United States)

    Francois, M.; Semin, B.; Auradou, H.; Vatteville, J.

    2010-06-01

    The proposed method, named Virtual Image Correlation, allows one to identify an analytical expression of the shape of a curvilinear object from its image. It uses a virtual beam, whose curvature field is expressed as a truncated mathematical series. The virtual beam width only needs to be close to the physical one; its gray level (in the transverse direction) is bell-shaped. The method consists in finding the coefficients of the series for which the correlation between physical and virtual beams is the best. The accuracy and the robustness of the method is shown by the mean of two examples. The first details a Young’s modulus identification from a cantilever beam image. The second is relative to a thermal plume image, that have a weak contrast and a lot of noise.

  9. Shape determination of unidimensional objects: the virtual image correlation method

    OpenAIRE

    Auradou H.; Vatteville J.; Semin B.; Francois M.

    2010-01-01

    The proposed method, named Virtual Image Correlation, allows one to identify an analytical expression of the shape of a curvilinear object from its image. It uses a virtual beam, whose curvature field is expressed as a truncated mathematical series. The virtual beam width only needs to be close to the physical one; its gray level (in the transverse direction) is bell-shaped. The method consists in finding the coefficients of the series for which the correlation between physical and virtual ...

  10. In Situ Correlated Molecular Imaging of Chemically Communicating Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, Paul W. [Univ. of Notre Dame, IN (United States); Shrout, J. D. [Univ. of Notre Dame, IN (United States); Sweedler, J. V. [Univ. of Illinois, Urbana-Champaign, IL (United States); Farrand, S. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2016-01-25

    This document constitutes the final technical report for DE-SC0006642, In Situ Correlated Molecular Imaging of Chemically Communicating Microbial Communities, a project carried out collaboratively by investigators at Notre Dame and UIUC. The work carried out under DOE support in this project produced advances in two areas: development of new highly sophisticated correlated imaging approaches and the application of these new tools to the growth and differentiation of microbial communities under a variety of environmental conditions. A significant effort involved the creation of technical enhancements and sampling approaches to allow us to advance heterocorrelated mass spectrometry imaging (MSI) and correlated Raman microscopy (CRM) from bacterial cultures and biofilms. We then exploited these measurement advances in heterocorrelated MS/CRM imaging to determine relationship of signaling molecules and excreted signaling molecules produced by P. aeruginosa to conditions relevant to the rhizosphere. In particular, we: (1) developed a laboratory testbed mimic for the rhizosphere to enable microbial growth on slides under controlled conditions; (2) integrated specific measurements of (a) rhamnolipids, (b) quinolone/quinolones, and (c) phenazines specific to P. aeruginosa; and (3) utilized the imaging tools to probe how messenger secretion, quorum sensing and swarming behavior are correlated with behavior.

  11. Case-based statistical learning applied to SPECT image classification

    Science.gov (United States)

    Górriz, Juan M.; Ramírez, Javier; Illán, I. A.; Martínez-Murcia, Francisco J.; Segovia, Fermín.; Salas-Gonzalez, Diego; Ortiz, A.

    2017-03-01

    Statistical learning and decision theory play a key role in many areas of science and engineering. Some examples include time series regression and prediction, optical character recognition, signal detection in communications or biomedical applications for diagnosis and prognosis. This paper deals with the topic of learning from biomedical image data in the classification problem. In a typical scenario we have a training set that is employed to fit a prediction model or learner and a testing set on which the learner is applied to in order to predict the outcome for new unseen patterns. Both processes are usually completely separated to avoid over-fitting and due to the fact that, in practice, the unseen new objects (testing set) have unknown outcomes. However, the outcome yields one of a discrete set of values, i.e. the binary diagnosis problem. Thus, assumptions on these outcome values could be established to obtain the most likely prediction model at the training stage, that could improve the overall classification accuracy on the testing set, or keep its performance at least at the level of the selected statistical classifier. In this sense, a novel case-based learning (c-learning) procedure is proposed which combines hypothesis testing from a discrete set of expected outcomes and a cross-validated classification stage.

  12. Applying a visual language for image processing as a graphical teaching tool in medical imaging

    Science.gov (United States)

    Birchman, James J.; Tanimoto, Steven L.; Rowberg, Alan H.; Choi, Hyung-Sik; Kim, Yongmin

    1992-05-01

    Typical user interaction in image processing is with command line entries, pull-down menus, or text menu selections from a list, and as such is not generally graphical in nature. Although applying these interactive methods to construct more sophisticated algorithms from a series of simple image processing steps may be clear to engineers and programmers, it may not be clear to clinicians. A solution to this problem is to implement a visual programming language using visual representations to express image processing algorithms. Visual representations promote a more natural and rapid understanding of image processing algorithms by providing more visual insight into what the algorithms do than the interactive methods mentioned above can provide. Individuals accustomed to dealing with images will be more likely to understand an algorithm that is represented visually. This is especially true of referring physicians, such as surgeons in an intensive care unit. With the increasing acceptance of picture archiving and communications system (PACS) workstations and the trend toward increasing clinical use of image processing, referring physicians will need to learn more sophisticated concepts than simply image access and display. If the procedures that they perform commonly, such as window width and window level adjustment and image enhancement using unsharp masking, are depicted visually in an interactive environment, it will be easier for them to learn and apply these concepts. The software described in this paper is a visual programming language for imaging processing which has been implemented on the NeXT computer using NeXTstep user interface development tools and other tools in an object-oriented environment. The concept is based upon the description of a visual language titled `Visualization of Vision Algorithms' (VIVA). Iconic representations of simple image processing steps are placed into a workbench screen and connected together into a dataflow path by the user. As

  13. Composite pseudocolor images: a technique to enhance the visual correlation between ventilation-perfusion lung images

    Science.gov (United States)

    Vaz de Carvalho, Carlos; Costa, Antonio A.; Seixas, M.; Ferreira, F. N.; Guedes, M. A.; Amaral, I.

    1993-07-01

    Lung ventilation and perfusion raw nuclear medicine images obtained from a gamma camera can be difficult to analyze on a per si basis. A method to optimize the visual correlation between these images was established through the use of new combination images: Composite Pseudo-Color (CPC) images. The major topic of this study is the assessment of the usefulness of this method in the detection of lung malfunction.

  14. NOAA-AVHRR image mosaics applied to vegetation identification

    Science.gov (United States)

    de Almeida, Maria d. G.; Ruddorff, Bernardo F.; Shimabukuro, Yosio E.

    2001-06-01

    In this paper, the maximum-value composite of images procedure from Normalized Difference Vegetation Index is used to get a cloud free image mosaic. The image mosaic is used to identify vegetation targets such as tropical forest, savanna and caatinga as well to make the vegetation cover mapping of Minas Gerais state, Brazil.

  15. High-speed image matching with coaxial holographic optical correlator

    Science.gov (United States)

    Ikeda, Kanami; Watanabe, Eriko

    2016-09-01

    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  16. Imaging in scattering media using correlation image sensors and sparse convolutional coding

    KAUST Repository

    Heide, Felix

    2014-10-17

    Correlation image sensors have recently become popular low-cost devices for time-of-flight, or range cameras. They usually operate under the assumption of a single light path contributing to each pixel. We show that a more thorough analysis of the sensor data from correlation sensors can be used can be used to analyze the light transport in much more complex environments, including applications for imaging through scattering and turbid media. The key of our method is a new convolutional sparse coding approach for recovering transient (light-in-flight) images from correlation image sensors. This approach is enabled by an analysis of sparsity in complex transient images, and the derivation of a new physically-motivated model for transient images with drastically improved sparsity.

  17. Correlation between electron-irradiation defects and applied stress in graphene: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Kida, Shogo; Yamamoto, Masaya; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki, E-mail: yasuda@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Tada, Kazuhiro [Department of Electrical and Control Systems Engineering, National Institute of Technology, Toyama College, Toyama 939-8630 (Japan)

    2015-09-15

    Molecular dynamics (MD) simulations are performed to study the correlation between electron irradiation defects and applied stress in graphene. The electron irradiation effect is introduced by the binary collision model in the MD simulation. By applying a tensile stress to graphene, the number of adatom-vacancy (AV) and Stone–Wales (SW) defects increase under electron irradiation, while the number of single-vacancy defects is not noticeably affected by the applied stress. Both the activation and formation energies of an AV defect and the activation energy of an SW defect decrease when a tensile stress is applied to graphene. Applying tensile stress also relaxes the compression stress associated with SW defect formation. These effects induced by the applied stress cause the increase in AV and SW defect formation under electron irradiation.

  18. Manifold learning based registration algorithms applied to multimodal images.

    Science.gov (United States)

    Azampour, Mohammad Farid; Ghaffari, Aboozar; Hamidinekoo, Azam; Fatemizadeh, Emad

    2014-01-01

    Manifold learning algorithms are proposed to be used in image processing based on their ability in preserving data structures while reducing the dimension and the exposure of data structure in lower dimension. Multi-modal images have the same structure and can be registered together as monomodal images if only structural information is shown. As a result, manifold learning is able to transform multi-modal images to mono-modal ones and subsequently do the registration using mono-modal methods. Based on this application, in this paper novel similarity measures are proposed for multi-modal images in which Laplacian eigenmaps are employed as manifold learning algorithm and are tested against rigid registration of PET/MR images. Results show the feasibility of using manifold learning as a way of calculating the similarity between multimodal images.

  19. Phase-shifting technique applied to circular harmonic-based joint transform correlator

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The phase-shifting technique is applied to the circular harmonic expansion-based joint transform correlator. Computer simulation has shown that the light efficiency and the discrimination capability are greatly enhanced, and the full rotation invariance is preserved after the phase-shifting technique has been used. A rotation-invariant optical pattern recognition with high discrimination capability and high light efficiency is obtained. The influence of the additive noise on the performance of the correlator is also investigated. However, the anti-noise capability of this kind of correlator still needs improving.

  20. Adaptive codebook selection schemes for image classification in correlated channels

    Science.gov (United States)

    Hu, Chia Chang; Liu, Xiang Lian; Liu, Kuan-Fu

    2015-09-01

    The multiple-input multiple-output (MIMO) system with the use of transmit and receive antenna arrays achieves diversity and array gains via transmit beamforming. Due to the absence of full channel state information (CSI) at the transmitter, the transmit beamforming vector can be quantized at the receiver and sent back to the transmitter by a low-rate feedback channel, called limited feedback beamforming. One of the key roles of Vector Quantization (VQ) is how to generate a good codebook such that the distortion between the original image and the reconstructed image is the minimized. In this paper, a novel adaptive codebook selection scheme for image classification is proposed with taking both spatial and temporal correlation inherent in the channel into consideration. The new codebook selection algorithm is developed to select two codebooks from the discrete Fourier transform (DFT) codebook, the generalized Lloyd algorithm (GLA) codebook and the Grassmannian codebook to be combined and used as candidates of the original image and the reconstructed image for image transmission. The channel is estimated and divided into four regions based on the spatial and temporal correlation of the channel and an appropriate codebook is assigned to each region. The proposed method can efficiently reduce the required information of feedback under the spatially and temporally correlated channels, where each region is adaptively. Simulation results show that in the case of temporally and spatially correlated channels, the bit-error-rate (BER) performance can be improved substantially by the proposed algorithm compared to the one with only single codebook.

  1. Variational multiparticle-multihole configuration mixing method applied to pairing correlations in nuclei

    CERN Document Server

    Pillet, N; Caurier, E

    2008-01-01

    Applying a variational multiparticle-multihole configuration mixing method whose purpose is to include correlations beyond the mean field in a unified way without particle number and Pauli principle violations, we investigate pairing-like correlations in the ground states of $ ^{116}$Sn,$ ^{106}$Sn and $ ^{100}$Sn. The same effective nucleon-nucleon interaction namely, the D1S parameterization of the Gogny force is used to derive both the mean field and correlation components of nuclear wave functions. Calculations are performed using an axially symetric representation. The structure of correlated wave functions, their convergence with respect to the number of particle-hole excitations and the influence of correlations on single-particle level spectra and occupation probabilities are analyzed and compared with results obtained with the same two-body effective interaction from BCS, Hartree-Fock-Bogoliubov and particle number projected after variation BCS approaches. Calculations of nuclear radii and the first ...

  2. Correlation of proton MR spectroscopy and diffusion tensor imaging

    NARCIS (Netherlands)

    Irwan, R; Sijens, PE; Potze, JH; Oudkerk, M

    2005-01-01

    Proton magnetic resonance spectroscopy (H-1-MRS) provides indices of neuronal damage. Diffusion tensor imaging (DTI) relates to water diffusivity and fiber tract orientation. A method to compare H-1-MRS and DTI findings was developed, tested on phantom and applied on normal brain. Point-resolved spe

  3. Correlation and image compression for limited-bandwidth CCD.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Douglas G.

    2005-07-01

    As radars move to Unmanned Aerial Vehicles with limited-bandwidth data downlinks, the amount of data stored and transmitted with each image becomes more significant. This document gives the results of a study to determine the effect of lossy compression in the image magnitude and phase on Coherent Change Detection (CCD). We examine 44 lossy compression types, plus lossless zlib compression, and test each compression method with over 600 CCD image pairs. We also derive theoretical predictions for the correlation for most of these compression schemes, which compare favorably with the experimental results. We recommend image transmission formats for limited-bandwidth programs having various requirements for CCD, including programs which cannot allow performance degradation and those which have stricter bandwidth requirements at the expense of CCD performance.

  4. Imaging of brain tumors with histological correlations. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, Antonios (ed.)

    2011-07-01

    This volume provides a deeper understanding of the diagnosis of brain tumors by correlating radiographic imaging features with the underlying pathological abnormalities. All modern imaging modalities are used to complete a diagnostic overview of brain tumors with emphasis on recent advances in diagnostic neuroradiology. High-quality illustrations depicting common and uncommon imaging characteristics of a wide range of brain tumors are presented and analysed, drawing attention to the ways in which these characteristics reflect different aspects of pathology. Important theoretical considerations are also discussed. Since the first edition, chapters have been revised and updated and new material has been added, including detailed information on the clinical application of functional MRI and diffusion tensor imaging. Radiologists and other clinicians interested in the current diagnostic approach to brain tumors will find this book to be an invaluable and enlightening clinical tool. (orig.)

  5. Incoherent Diffractive Imaging via Intensity Correlations of Hard X Rays

    Science.gov (United States)

    Classen, Anton; Ayyer, Kartik; Chapman, Henry N.; Röhlsberger, Ralf; von Zanthier, Joachim

    2017-08-01

    Established x-ray diffraction methods allow for high-resolution structure determination of crystals, crystallized protein structures, or even single molecules. While these techniques rely on coherent scattering, incoherent processes like fluorescence emission—often the predominant scattering mechanism—are generally considered detrimental for imaging applications. Here, we show that intensity correlations of incoherently scattered x-ray radiation can be used to image the full 3D arrangement of the scattering atoms with significantly higher resolution compared to conventional coherent diffraction imaging and crystallography, including additional three-dimensional information in Fourier space for a single sample orientation. We present a number of properties of incoherent diffractive imaging that are conceptually superior to those of coherent methods.

  6. Unsupervised Neural Techniques Applied to MR Brain Image Segmentation

    Directory of Open Access Journals (Sweden)

    A. Ortiz

    2012-01-01

    Full Text Available The primary goal of brain image segmentation is to partition a given brain image into different regions representing anatomical structures. Magnetic resonance image (MRI segmentation is especially interesting, since accurate segmentation in white matter, grey matter and cerebrospinal fluid provides a way to identify many brain disorders such as dementia, schizophrenia or Alzheimer’s disease (AD. Then, image segmentation results in a very interesting tool for neuroanatomical analyses. In this paper we show three alternatives to MR brain image segmentation algorithms, with the Self-Organizing Map (SOM as the core of the algorithms. The procedures devised do not use any a priori knowledge about voxel class assignment, and results in fully-unsupervised methods for MRI segmentation, making it possible to automatically discover different tissue classes. Our algorithm has been tested using the images from the Internet Brain Image Repository (IBSR outperforming existing methods, providing values for the average overlap metric of 0.7 for the white and grey matter and 0.45 for the cerebrospinal fluid. Furthermore, it also provides good results for high-resolution MR images provided by the Nuclear Medicine Service of the “Virgen de las Nieves” Hospital (Granada, Spain.

  7. Adaptive image segmentation applied to plant reproduction by tissue culture

    Science.gov (United States)

    Vazquez Rueda, Martin G.; Hahn, Federico; Zapata, Jose L.

    1997-04-01

    This paper presents that experimental results obtained on indoor tissue culture using the adaptive image segmentation system. The performance of the adaptive technique is contrasted with different non-adaptive techniques commonly used in the computer vision field to demonstrate the improvement provided by the adaptive image segmentation system.

  8. Imaged document information location and extraction using an optical correlator

    Science.gov (United States)

    Stalcup, Bruce W.; Dennis, Phillip W.; Dydyk, Robert B.

    1999-12-01

    Today, the paper document is fast becoming a thing of the past. With the rapid development of fast, inexpensive computing and storage devices, many government and private organizations are archiving their documents in electronic form (e.g., personnel records, medical records, patents, etc.). Many of these organizations are converting their paper archives to electronic images, which are then stored in a computer database. Because of this, there is a need to efficiently organize this data into comprehensive and accessible information resources and provide for rapid access to the information contained within these imaged documents. To meet this need, Litton PRC and Litton Data Systems Division are developing a system, the Imaged Document Optical Correlation and Conversion System (IDOCCS), to provide a total solution to the problem of managing and retrieving textual and graphic information from imaged document archives. At the heart of IDOCCS, optical correlation technology provide a means for the search and retrieval of information from imaged documents. IDOCCS can be used to rapidly search for key words or phrases within the imaged document archives and has the potential to determine the types of languages contained within a document. In addition, IDOCCS can automatically compare an input document with the archived database to determine if it is a duplicate, thereby reducing the overall resources required to maintain and access the document database. Embedded graphics on imaged pages can also be exploited, e.g., imaged documents containing an agency's seal or logo can be singled out. In this paper, we present a description of IDOCCS as well as preliminary performance results and theoretical projections.

  9. Improved Bat Algorithm Applied to Multilevel Image Thresholding

    Directory of Open Access Journals (Sweden)

    Adis Alihodzic

    2014-01-01

    Full Text Available Multilevel image thresholding is a very important image processing technique that is used as a basis for image segmentation and further higher level processing. However, the required computational time for exhaustive search grows exponentially with the number of desired thresholds. Swarm intelligence metaheuristics are well known as successful and efficient optimization methods for intractable problems. In this paper, we adjusted one of the latest swarm intelligence algorithms, the bat algorithm, for the multilevel image thresholding problem. The results of testing on standard benchmark images show that the bat algorithm is comparable with other state-of-the-art algorithms. We improved standard bat algorithm, where our modifications add some elements from the differential evolution and from the artificial bee colony algorithm. Our new proposed improved bat algorithm proved to be better than five other state-of-the-art algorithms, improving quality of results in all cases and significantly improving convergence speed.

  10. Photon-number correlation for quantum enhanced imaging and sensing

    Science.gov (United States)

    Meda, A.; Losero, E.; Samantaray, N.; Scafirimuto, F.; Pradyumna, S.; Avella, A.; Ruo-Berchera, I.; Genovese, M.

    2017-09-01

    In this review we present the potentialities and the achievements of the use of non-classical photon-number correlations in twin-beam states for many applications, ranging from imaging to metrology. Photon-number correlations in the quantum regime are easily produced and are rather robust against unavoidable experimental losses, and noise in some cases, if compared to the entanglement, where losing one photon can completely compromise the state and its exploitable advantages. Here, we will focus on quantum enhanced protocols in which only phase-insensitive intensity measurements (photon-number counting) are performed, which allow probing the transmission/absorption properties of a system, leading, for example, to innovative target detection schemes in a strong background. In this framework, one of the advantages is that the sources experimentally available emit a wide number of pair-wise correlated modes, which can be intercepted and exploited separately, for example by many pixels of a camera, providing a parallelism, essential in several applications, such as wide-field sub-shot-noise imaging and quantum enhanced ghost imaging. Finally, non-classical correlation enables new possibilities in quantum radiometry, e.g. the possibility of absolute calibration of a spatial resolving detector from the on-off single-photon regime to the linear regime in the same setup.

  11. Extracting flat-field images from scene-based image sequences using phase correlation

    Science.gov (United States)

    Caron, James N.; Montes, Marcos J.; Obermark, Jerome L.

    2016-06-01

    Flat-field image processing is an essential step in producing high-quality and radiometrically calibrated images. Flat-fielding corrects for variations in the gain of focal plane array electronics and unequal illumination from the system optics. Typically, a flat-field image is captured by imaging a radiometrically uniform surface. The flat-field image is normalized and removed from the images. There are circumstances, such as with remote sensing, where a flat-field image cannot be acquired in this manner. For these cases, we developed a phase-correlation method that allows the extraction of an effective flat-field image from a sequence of scene-based displaced images. The method uses sub-pixel phase correlation image registration to align the sequence to estimate the static scene. The scene is removed from sequence producing a sequence of misaligned flat-field images. An average flat-field image is derived from the realigned flat-field sequence.

  12. Fresnel incoherent correlation holography and its imaging properties

    Science.gov (United States)

    Wang, Zhipeng; Ma, Haotong; Ren, Ge; Xie, Zongliang; Yu, Huan

    2016-09-01

    The incoherent digital holography makes it possible to record holograms under incoherent illumination, which lowers requirement for the coherence of light sources and results in expanding its application to white-light and fluorescence illuminating circumstances. The Fresnel Incoherent Correlation Holography (FINCH) technology achieves diverging the incident beam and shifting phase by mounting phase masks on the phase modulator. Then it obtains holograms with phase difference and reconstructs the image. In this paper, we explain the principles of the FINCH technology, and introduce the n-step phase-shifting method which is utilized to eliminate the twin image and bias term in holograms. During the research, we studied what impact the term n may have on imaging performance, compared imaging performances when different phase masks are mounted on SLM, and established simulation system on imaging with which imaging performances are deeply inspected. At last, it is shown in the research that the FINCH technology could record holograms of objects, from which clear images could be reconstructed digitally.

  13. An extension of digital volume correlation for multimodality image registration

    Science.gov (United States)

    Tudisco, E.; Jailin, C.; Mendoza, A.; Tengattini, A.; Andò, E.; Hall, Stephen A.; Viggiani, Gioacchino; Hild, F.; Roux, S.

    2017-09-01

    The question of registering two images (or image volumes) acquired with different modalities, and thus exhibiting different contrast, at different positions is addressed based on an extension of global digital image (or volume) correlation. A specific comparison metric is introduced allowing the signature of the different phases to be related. A first solution consists of a Gaussian mixture to describe the joint distribution of gray levels, which not only provides a matching of both images, but also offers a natural segmentation indicator. A second ‘self-adapting’ solution does not include any postulated a priori model for the joint histogram and leads to a registration of the images based on their initial histograms. The algorithm is implemented with a pyramidal multiscale framework for the sake of robustness. The proposed multiscale technique is tested on two 3D images obtained from x-ray and neutron tomography respectively. The proposed approach brings the two images to coincidence with a sub-pixel accuracy and allows for a ‘natural’ segmentation of the different phases.

  14. Prevalence and correlates of body image dissatisfaction in postmenopausal women.

    Science.gov (United States)

    Ginsberg, Rebecca L; Tinker, Lesley; Liu, Jingmin; Gray, James; Sangi-Haghpeykar, Haleh; Manson, JoAnn E; Margolis, Karen L

    2016-01-01

    Dissatisfaction with one's body image is widespread and can have serious health consequences; however, research about its prevalence and correlates in older women is limited. We analyzed data from 75,256 women participating in the Women's Health Initiative Observational Study, a longitudinal study of postmenopausal women's health. Measures used in the study were collected at baseline and/or the third year of follow-up between 1993 and 2002. The majority of participants (83%) in this study were dissatisfied with their bodies because they perceived themselves as heavier than their ideal. Overall, the multiple and significant correlates of body image dissatisfaction explained 36.2% of the variance in the body image dissatisfaction score, with body mass index (BMI) and change in BMI being the two most important contributors to explaining the variance. The results of this study suggest future research should focus on the utility of interventions to reduce dissatisfaction with body image in postmenopausal women that target either maintenance of a lower BMI through diet and exercise, and/or body acceptance. Further, future research should aim to identify factors in addition to body size that drive body image dissatisfaction.

  15. Accurate measurement of curvilinear shapes by Virtual Image Correlation

    Science.gov (United States)

    Semin, B.; Auradou, H.; François, M. L. M.

    2011-10-01

    The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C∞ (and not a finite set of locations or pixels) thus curvatures and slopes, often of great interest in science, are given with good confidence. The proposed Virtual Image Correlation (VIC) method uses a virtual beam, an image which consists in a lateral expansion of the curve with a bell-shaped gray level. This figure is deformed until it fits the best the physical image with a method issued from the Digital Image Correlation method in use in solid mechanics. The precision of the identification is studied in a benchmark and successfully compared to two state-of-the-art methods. Three practical examples are given: a bar bending under its own weight, a thin fiber transported by a flow within a fracture and a thermal front. The first allows a comparison with theoretical solution, the second shows the ability of the method to deal with complex shapes and crossings and the third deals with ill-defined image.

  16. An improved fast fractal image compression using spatial texture correlation

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Wang Yuan-Xing; Yun Jiao-Jiao

    2011-01-01

    This paper utilizes a spatial texture correlation and the intelligent classification algorithm (ICA) search strategy to speed up the encoding process and improve the bit rate for fractal image compression.Texture features is one of the most important properties for the representation of an image.Entropy and maximum entry from co-occurrence matrices are used for representing texture features in an image.For a range block,concerned domain blocks of neighbouring range blocks with similar texture features can be searched.In addition,domain blocks with similar texture features are searched in the ICA search process.Experiments show that in comparison with some typical methods,the proposed algorithm significantly speeds up the encoding process and achieves a higher compression ratio,with a slight diminution in the quality of the reconstructed image; in comparison with a spatial correlation scheme,the proposed scheme spends much less encoding time while the compression ratio and the quality of the reconstructed image are almost the same.

  17. Image pre-filtering for measurement error reduction in digital image correlation

    Science.gov (United States)

    Zhou, Yihao; Sun, Chen; Song, Yuntao; Chen, Jubing

    2015-02-01

    In digital image correlation, the sub-pixel intensity interpolation causes a systematic error in the measured displacements. The error increases toward high-frequency component of the speckle pattern. In practice, a captured image is usually corrupted by additive white noise. The noise introduces additional energy in the high frequencies and therefore raises the systematic error. Meanwhile, the noise also elevates the random error which increases with the noise power. In order to reduce the systematic error and the random error of the measurements, we apply a pre-filtering to the images prior to the correlation so that the high-frequency contents are suppressed. Two spatial-domain filters (binomial and Gaussian) and two frequency-domain filters (Butterworth and Wiener) are tested on speckle images undergoing both simulated and real-world translations. By evaluating the errors of the various combinations of speckle patterns, interpolators, noise levels, and filter configurations, we come to the following conclusions. All the four filters are able to reduce the systematic error. Meanwhile, the random error can also be reduced if the signal power is mainly distributed around DC. For high-frequency speckle patterns, the low-pass filters (binomial, Gaussian and Butterworth) slightly increase the random error and Butterworth filter produces the lowest random error among them. By using Wiener filter with over-estimated noise power, the random error can be reduced but the resultant systematic error is higher than that of low-pass filters. In general, Butterworth filter is recommended for error reduction due to its flexibility of passband selection and maximal preservation of the allowed frequencies. Binomial filter enables efficient implementation and thus becomes a good option if computational cost is a critical issue. While used together with pre-filtering, B-spline interpolator produces lower systematic error than bicubic interpolator and similar level of the random

  18. Quality assessment of butter cookies applying multispectral imaging

    DEFF Research Database (Denmark)

    Stenby Andresen, Mette; Dissing, Bjørn Skovlund; Løje, Hanne

    2013-01-01

    A method for characterization of butter cookie quality by assessing the surface browning and water content using multispectral images is presented. Based on evaluations of the browning of butter cookies, cookies were manually divided into groups. From this categorization, reference values were...... in a forced convection electrically heated oven. In addition to the browning score, a model for predicting the average water content based on the same images is presented. This shows how multispectral images of butter cookies may be used for the assessment of different quality parameters. Statistical analysis...

  19. The problem of applying information theory to efficient image transmission.

    Science.gov (United States)

    Sakrison, D. J.

    1973-01-01

    The main ideas of Shannon's (1948, 1960) theory of source encoding with a fidelity constraint, more commonly known as rate distortion theory, are summarized. The theory was specifically intended to provide a theoretical basis for efficient transmission of information such as images. What the theory has to contribute to the problem is demonstrated. Difficulties that impeded application of the theory to image transmission, and current efforts to solve these difficulties are discussed.

  20. Upconversion applied for mid-IR hyperspectral image acquisition

    DEFF Research Database (Denmark)

    Tidemand-Lichtenberg, Peter; Kehlet, Louis Martinus; Sanders, Nicolai Højer;

    2015-01-01

    Different schemes for upconversion mid-IR hyperspectral imaging is implemented and compared in terms of spectral coverage, spectral resolution, speed and noise. Phasematch scanning and scanning of the object within the field of view is considered.......Different schemes for upconversion mid-IR hyperspectral imaging is implemented and compared in terms of spectral coverage, spectral resolution, speed and noise. Phasematch scanning and scanning of the object within the field of view is considered....

  1. Subpixel Accuracy Analysis of Phase Correlation Shift Measurement Methods Applied to Satellite Imagery

    Directory of Open Access Journals (Sweden)

    S.M. Badwai

    2013-01-01

    Full Text Available the key point of super resolution process is the accurate measuring of sub-pixel shift. Any tiny error in measuring such shift leads to an incorrect image focusing. In this paper, methodology of measuring sub-pixel shift using Phase correlation (PC are evaluated using different window functions, then modified version of (PC method using high pass filter (HPF is introduced . Comprehensive analysis and assessment of (PC methods shows that different natural features yield different shift measurements. It is concluded that there is no universal window function for measuring shift; it mainly depends on the features in the satellite images. Even the question of which window is optimal of particular feature is generally remains open. This paper presents the design of a method for obtaining high accuracy sub pixel shift phase correlation using (HPF.The proposed method makes the change in the different locations that lack of edges easy.

  2. Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

    Directory of Open Access Journals (Sweden)

    Benjamin Pollard

    2016-04-01

    Full Text Available Intermolecular interactions and nanoscale phase separation govern the properties of many molecular soft-matter systems. Here, we combine infrared vibrational scattering scanning near-field optical microscopy (IR s-SNOM with force–distance spectroscopy for simultaneous characterization of both nanoscale optical and nanomechanical molecular properties through hybrid imaging. The resulting multichannel images and correlative analysis of chemical composition, spectral IR line shape, modulus, adhesion, deformation, and dissipation acquired for a thin film of a nanophase separated block copolymer (PS-b-PMMA reveal complex structural variations, in particular at domain interfaces, not resolved in any individual signal channel alone. These variations suggest that regions of multicomponent chemical composition, such as the interfacial mixing regions between microdomains, are correlated with high spatial heterogeneity in nanoscale material properties.

  3. Middle cerebellar peduncles:Magnetic resonance imaging and pathophysiologic correlate

    Institute of Scientific and Technical Information of China (English)

    Humberto Morales; Thomas Tomsick

    2015-01-01

    We describe common and less common diseases that can cause magnetic resonance signal abnormalities of middle cerebellar peduncles(MCP), offering a systematicapproach correlating imaging findings with clinical clues and pathologic mechanisms. Myelin abnormalities, different types of edema or neurodegenerative processes, can cause areas of abnormal T2 signal, variable enhancement, and patterns of diffusivity of MCP. Pathologies such as demyelinating disorders or certain neurodegenerative entities(e.g., multiple system atrophy or fragile X-associated tremor-ataxia syndrome) appear to have predilection for MCP. Careful evaluation of concomitant imaging findings in the brain or brainstem; and focused correlation with key clinical findings such as immunosuppression for progressive multifocal leukoencephalopahty; hypertension, post-transplant status or high dose chemotherapy for posterior reversible encephalopathy; electrolyte disorders for myelinolysis or suspected toxic-drug related encephalopathy; would yield an appropriate and accurate differential diagnosis in the majority of cases.

  4. Correlative investigations of craniospinal anatomy and pathology with computed tomography, magnetic resonance imaging and cryomicrotomy.

    Science.gov (United States)

    Pech, P

    1988-01-01

    A correlative computed tomographic-anatomic method was applied to multiplanar anatomic studies. The method was particularly valuable for comparative anatomic investigations of complex regions of the central nervous system. The description of CT and MR anatomy in this thesis is based either on direct CT-anatomic correlation of the same specimen, or on indirect MR-anatomic correlation with cryosectional images from cadavers. In sagittal partial saturation MR images with short repetition times, the pituitary fossa in 41 normal volunteers appeared inhomogeneous. A postero-inferiorly located high intensity signal correlated with an intrasellar fat pad in sagittal cryosectional images. The height of the pituitary gland in 38 normal volunteers was usually less than 8 mm and its upper surface was flat or concave. The cavernous sinus anatomy was studied in coronal and axial MR planes in seven normal volunteers and 15 patients in correlation with cryosectional images. The intracavernous cranial nerves were best shown in the coronal plane, in partial saturation and inversion recovery sequences and displayed as foci of high signals intensity. MR signs of a parasellar mass included obliteration of intracavernous venous spaces, displacement of the intracavernous portion of the internal carotid artery and bulging of the lateral wall of the cavernous sinus. The topographic anatomy of the cervical neuroforamina was investigated in axial, sagittal, coronal and oblique planes in a correlative CT-anatomic investigation in 19 specimens. In four normal volunteers, the surface coil MR images of the cervical neuroforamina were correlated with cryosectional images. Surface coil MR images in a plane perpendicular to the cervical nerve roots allowed to determine their relationship to intraforaminal structures and the boundaries of the foramen. The dorsal and ventral nerve roots were demonstrated with both CT and MRI. They were located in the lower half of the foramen at and below the

  5. Long-correlation image models for textures with circular and elliptical correlation structures.

    Science.gov (United States)

    Eom, K B

    2001-01-01

    A class of random field model having long-correlation characteristics is introduced. Unlike earlier approaches in long-correlation models, the correlation structure is isotropic or elliptical in this new class of random field model. The new model has an advantage of modeling diverse real textures with less than five model parameters. Further, the model parameters match with intuitive attributes of textures, such as smoothness, pattern size, elongation or orientation of patterns. The new long-correlation models are based on the fractional differencing of a two-dimensional (2-D) autoregressive polynomial defined by eight symmetric neighbors, and they are either persistent or periodic models depending whether the roots of the polynomial are real or imaginary. A comprehensive three-step algorithm for parameter estimation is developed, and the statistical properties of the estimators are also discussed. The validity of the new model in modeling textures is tested by synthesizing images from manually selected parameters as well as parameters estimated from real textures. It is shown that an image with desired attributes can be synthesized by selecting proper values of the parameters. Further, it is shown that the models introduced can be used in modeling wide range of textures by synthesizing images resembling real textures from estimated parameters.

  6. Image remapping strategies applied as protheses for the visually impaired

    Science.gov (United States)

    Johnson, Curtis D.

    1993-01-01

    Maculopathy and retinitis pigmentosa (rp) are two vision defects which render the afflicted person with impaired ability to read and recognize visual patterns. For some time there has been interest and work on the use of image remapping techniques to provide a visual aid for individuals with these impairments. The basic concept is to remap an image according to some mathematical transformation such that the image is warped around a maculopathic defect (scotoma) or within the rp foveal region of retinal sensitivity. NASA/JSC has been pursuing this research using angle invariant transformations with testing of the resulting remapping using subjects and facilities of the University of Houston, College of Optometry. Testing is facilitated by use of a hardware device, the Programmable Remapper, to provide the remapping of video images. This report presents the results of studies of alternative remapping transformations with the objective of improving subject reading rates and pattern recognition. In particular a form of conformal transformation was developed which provides for a smooth warping of an image around a scotoma. In such a case it is shown that distortion of characters and lines of characters is minimized which should lead to enhanced character recognition. In addition studies were made of alternative transformations which, although not conformal, provide for similar low character distortion remapping. A second, non-conformal transformation was studied for remapping of images to aid rp impairments. In this case a transformation was investigated which allows remapping of a vision field into a circular area representing the foveal retina region. The size and spatial representation of the image are selectable. It is shown that parametric adjustments allow for a wide variation of how a visual field is presented to the sensitive retina. This study also presents some preliminary considerations of how a prosthetic device could be implemented in a practical sense, vis

  7. CORRELATION PROCESSING OF DIGITAL OPTICAL IMAGES FOR SOLVING CRIMINALISTIC PROBLEMS

    Directory of Open Access Journals (Sweden)

    V. L. Kozlov

    2015-01-01

    Full Text Available The correlation processing of optical digital images of expert research objects is promising to improve the quality, reliability and representativeness of the research. The development of computer algorithms for expert investigations by using correlation analysis methods for solving such problems of criminology, as a comparison of color-tone image parameters impressions of seals and stamps, and measurement of the rifling profile trace of the barrel on the bullet is the purpose of the work. A method and software application for measurement of linear, angular and altitude characteristics of the profile (micro relief of the rifling traces of the barrel on the bullet for judicial-ballistic tests is developed. Experimental results testify to a high overall performance of the developed program application and confirm demanded accuracy of spent measurements. Technique and specialized program application for the comparison of color-tone image parameters impressions of seals and stamps, reflecting degree and character of painting substance distribution in strokes has been developed. It improves presentation and objectivity of tests, and also allows to reduce their carrying out terms. The technique of expert interpretation of correlation analysis results has been offered. Reliability of the received results has been confirmed by experimental researches and has been checked up by means of other methods.

  8. Cross Correlation versus Mutual Information for Image Mosaicing

    Directory of Open Access Journals (Sweden)

    Sherin Ghannam

    2013-12-01

    Full Text Available This paper reviews the concept of image mosaicing and presents a comparison between two of the most common image mosaicing techniques. The first technique is based on normalized cross correlation (NCC for registering overlapping 2D images of a 3D scene. The second is based on mutual information (MI. The experimental results demonstrate that the two techniques have a similar performance in most cases but there are some interesting differences. The choice of a distinctive template is critical when working with NCC. On the other hand, when using MI, the registration procedure was able to provide acceptable performance even without distinctive templates. But generally the performance when using MI with large rotation angles was not accurate as with NCC.

  9. Integrated global digital image correlation for interface delamination characterization

    KAUST Repository

    Hoefnagels, Johan P.M.

    2013-07-23

    Interfacial delamination is a key reliability challenge in composites and micro-electronic systems due to (high-density) integration of dissimilar materials. Predictive finite element models are used to minimize delamination failures during design, but require accurate interface models to capture (irreversible) crack initiation and propagation behavior observed in experiments. Therefore, an Integrated Global Digital Image Correlation (I-GDIC) strategy is developed for accurate determination of mechanical interface behavior from in-situ delamination experiments. Recently, a novel miniature delamination setup was presented that enables in-situ microscopic characterization of interface delamination while sensitively measuring global load-displacement curves for all mode mixities. Nevertheless, extraction of detailed mechanical interface behavior from measured images is challenging, because deformations are tiny and measurement noise large. Therefore, an advanced I-GDIC methodology is developed which correlates the image patterns by only deforming the images using kinematically-admissible \\'eigenmodes\\' that correspond to the few parameters controlling the interface tractions in an analytic description of the crack tip deformation field, thereby greatly enhancing accuracy and robustness. This method is validated on virtual delamination experiments, simulated using a recently developed self-adaptive cohesive zone (CZ) finite element framework. © The Society for Experimental Mechanics, Inc. 2014.

  10. A multilateral filtering method applied to airplane runway image

    CERN Document Server

    Yu, Zhang; Run-quan, Wang

    2008-01-01

    By considering the features of the airport runway image filtering, an improved bilateral filtering method was proposed which can remove noise with edge preserving. Firstly the steerable filtering decomposition is used to calculate the sub-band parameters of 4 orients, and the texture feature matrix is then obtained from the sub-band local median energy. The texture similar, the spatial closer and the color similar functions are used to filter the image.The effect of the weighting function parameters is qualitatively analyzed also. In contrast with the standard bilateral filter and the simulation results for the real airport runway image show that the multilateral filtering is more effective than the standard bilateral filtering.

  11. Personal Computer (PC) based image processing applied to fluid mechanics

    Science.gov (United States)

    Cho, Y.-C.; Mclachlan, B. G.

    1987-01-01

    A PC based image processing system was employed to determine the instantaneous velocity field of a two-dimensional unsteady flow. The flow was visualized using a suspension of seeding particles in water, and a laser sheet for illumination. With a finite time exposure, the particle motion was captured on a photograph as a pattern of streaks. The streak pattern was digitized and processed using various imaging operations, including contrast manipulation, noise cleaning, filtering, statistical differencing, and thresholding. Information concerning the velocity was extracted from the enhanced image by measuring the length and orientation of the individual streaks. The fluid velocities deduced from the randomly distributed particle streaks were interpolated to obtain velocities at uniform grid points. For the interpolation a simple convolution technique with an adaptive Gaussian window was used. The results are compared with a numerical prediction by a Navier-Stokes computation.

  12. Noise in laser speckle correlation and imaging techniques

    CERN Document Server

    Skipetrov, Sergey E; Cerbino, Roberto; Zakharov, Pavel; Weber, Bruno; Scheffold, Frank

    2010-01-01

    We study the noise of the intensity variance and of the intensity correlation and structure functions measured in light scattering from a random medium in the case when these quantities are obtained by averaging over a finite number N of pixels of a digital camera. We show that the noise scales as 1/N in all cases and that it is sensitive to correlations of signals corresponding to adjacent pixels as well as to the effective time averaging (due to the finite sampling time) and spatial averaging (due to the finite pixel size). Our results provide a guide to estimation of noise level in such applications as the multi-speckle dynamic light scattering, time-resolved correlation spectroscopy, speckle visibility spectroscopy, laser speckle imaging etc.

  13. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    Science.gov (United States)

    Fan Zhu; Rodriguez Gonzalez, David; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  14. Applying BAT Evolutionary Optimization to Image-Based Visual Servoing

    Directory of Open Access Journals (Sweden)

    Marco Perez-Cisneros

    2015-01-01

    Full Text Available This paper presents a predictive control strategy for an image-based visual servoing scheme that employs evolutionary optimization. The visual control task is approached as a nonlinear optimization problem that naturally handles relevant visual servoing constraints such as workspace limitations and visibility restrictions. As the predictive scheme requires a reliable model, this paper uses a local model that is based on the visual interaction matrix and a global model that employs 3D trajectory data extracted from a quaternion-based interpolator. The work assumes a free-flying camera with 6-DOF simulation whose results support the discussion on the constraint handling and the image prediction scheme.

  15. Students' Images of Problem Contexts when Solving Applied Problems

    Science.gov (United States)

    Moore, Kevin C.; Carlson, Marilyn P.

    2012-01-01

    This article reports findings from an investigation of precalculus students' approaches to solving novel problems. We characterize the images that students constructed during their solution attempts and describe the degree to which they were successful in imagining how the quantities in a problem's context change together. Our analyses revealed…

  16. Students' Images of Problem Contexts when Solving Applied Problems

    Science.gov (United States)

    Moore, Kevin C.; Carlson, Marilyn P.

    2012-01-01

    This article reports findings from an investigation of precalculus students' approaches to solving novel problems. We characterize the images that students constructed during their solution attempts and describe the degree to which they were successful in imagining how the quantities in a problem's context change together. Our analyses revealed…

  17. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    Science.gov (United States)

    Álvarez López, Yuri; Martínez Lorenzo, José Ángel

    2017-01-01

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated. PMID:28098841

  18. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers.

    Science.gov (United States)

    López, Yuri Álvarez; Lorenzo, José Ángel Martínez

    2017-01-15

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  19. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    Directory of Open Access Journals (Sweden)

    Yuri Álvarez López

    2017-01-01

    Full Text Available One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  20. High-quality image magnification applying Gerchberg-Papoulis iterative algorithm with discrete cosine transform

    Science.gov (United States)

    Shinbori, Eiji; Takagi, Mikio

    1992-11-01

    A new image magnification method, called 'IM-GPDCT' (image magnification applying the Gerchberg-Papoulis (GP) iterative algorithm with discrete cosine transform (DCT)), is described and its performance evaluated. This method markedly improves image quality of a magnified image using a concept which restores the spatial high frequencies which are conventionally lost due to use of a low pass filter. These frequencies are restored using two known constraints applied during iterative DCT: (1) correct information in a passband is known and (2) the spatial extent of an image is finite. Simulation results show that the IM- GPDCT outperforms three conventional interpolation methods from both a restoration error and image quality standpoint.

  1. A Correlated Microwave-Acoustic Imaging method for early-stage cancer detection.

    Science.gov (United States)

    Gao, Fei; Zheng, Yuanjin

    2012-01-01

    Microwave-based imaging technique shows large potential in detecting early-stage cancer due to significant dielectric contrast between tumor and surrounding healthy tissue. In this paper, we present a new way named Correlated Microwave-Acoustic Imaging (CMAI) of combining two microwave-based imaging modalities: confocal microwave imaging(CMI) by detecting scattered microwave signal, and microwave-induced thermo-acoustic imaging (TAI) by detecting induced acoustic signal arising from microwave energy absorption and thermal expansion. Necessity of combining CMI and TAI is analyzed theoretically, and by applying simple algorithm to CMI and TAI separately, we propose an image correlation approach merging CMI and TAI together to achieve better performance in terms of resolution and contrast. Preliminary numerical simulation shows promising results in case of low contrast and large variation scenarios. A UWB transmitter is designed and tested for future complete system implementation. This preliminary study inspires us to develop a new medical imaging modality CMAI to achieve real-time, high resolution and high contrast simultaneously.

  2. Digital image correlation based on a fast convolution strategy

    Science.gov (United States)

    Yuan, Yuan; Zhan, Qin; Xiong, Chunyang; Huang, Jianyong

    2017-10-01

    In recent years, the efficiency of digital image correlation (DIC) methods has attracted increasing attention because of its increasing importance for many engineering applications. Based on the classical affine optical flow (AOF) algorithm and the well-established inverse compositional Gauss-Newton algorithm, which is essentially a natural extension of the AOF algorithm under a nonlinear iterative framework, this paper develops a set of fast convolution-based DIC algorithms for high-efficiency subpixel image registration. Using a well-developed fast convolution technique, the set of algorithms establishes a series of global data tables (GDTs) over the digital images, which allows the reduction of the computational complexity of DIC significantly. Using the pre-calculated GDTs, the subpixel registration calculations can be implemented efficiently in a look-up-table fashion. Both numerical simulation and experimental verification indicate that the set of algorithms significantly enhances the computational efficiency of DIC, especially in the case of a dense data sampling for the digital images. Because the GDTs need to be computed only once, the algorithms are also suitable for efficiently coping with image sequences that record the time-varying dynamics of specimen deformations.

  3. Correlation of calculated CNR and signal detectability on MR images

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Akio [Kyoto City Hospital (Japan); Higashida, Mitsuji; Yamazaki, Masaru; Inoue, Hiroshi

    1998-06-01

    To calculate the contrast-to-noise ratio (CNR) on magnetic resonance images, an equation selected to match each study is commonly used. The CNR values calculated using these equations may have their own characteristics. Therefore, the characteristics of four commonly calculated CNRs were evaluated in comparison with signal detectability. For the calculation of CNR, a phantom with five different solutions of CuSO{sub 4} was imaged using various scan sequences with different TR and NEX. These images, which had different levels of noise and contrast, were measured for averaged signal intensity and standard deviation of noise in the same ROIs (regions of interest). To define signal detectability, Burger`s phantom soaked in the CuSO{sub 4} solution was imaged with the same pulse sequences used to evaluate CNR. Burger`s phantom images were evaluated by five observers with a 50% confidence level. The characteristics of each CNR value were evaluated by correlating them with signal detectability. The results showed that some calculated CNRs indicated the noise element, but contrast element. From the point of view of signal detectability, the equation using the average of local variance and global variance with respect to coarse pixels was superior to others. (author)

  4. Uremic Encephalopathy: MR Imaging Findings and Clinical Correlation.

    Science.gov (United States)

    Kim, D M; Lee, I H; Song, C J

    2016-09-01

    Uremic encephalopathy is a metabolic disorder in patients with renal failure. The purpose of this study was to describe the MR imaging findings of uremic encephalopathy. This study retrospectively reviewed MR imaging findings in 10 patients with clinically proved uremic encephalopathy between May 2005 and December 2014. Parameters evaluated were lesion location and appearance; MR signal intensity of the lesions on T1WI, T2WI, and T2 fluid-attenuated inversion recovery images; the presence or absence of restricted diffusion on diffusion-weighted images and apparent diffusion coefficient maps; and the reversibility of documented signal-intensity abnormalities on follow-up MR imaging. MR imaging abnormalities accompanying marked elevation of serum creatinine (range, 4.3-11.7 mg/dL) were evident in the 10 patients. Nine patients had a history of chronic renal failure with expansile bilateral basal ganglia lesions, and 1 patient with acute renal failure had reversible largely cortical lesions. Two of 6 patients with available arterial blood gas results had metabolic acidosis. All basal ganglia lesions showed expansile high signal intensity (lentiform fork sign) on T2WI. Varied levels of restricted diffusion and a range of signal intensities on DWI were evident and were not correlated with serum Cr levels. All cortical lesions demonstrated high signal intensity on T2WI. Four patients with follow-up MR imaging after hemodialysis showed complete resolution of all lesions. The lentiform fork sign is reliable in the early diagnosis of uremic encephalopathy, regardless of the presence of metabolic acidosis. Cytotoxic edema and/or vasogenic edema on DWI/ADC maps may be associated with uremic encephalopathy. © 2016 by American Journal of Neuroradiology.

  5. Scanning tomographic particle image velocimetry applied to a turbulent jet

    KAUST Repository

    Casey, T. A.

    2013-02-21

    We introduce a modified tomographic PIV technique using four high-speed video cameras and a scanning pulsed laser-volume. By rapidly illuminating adjacent subvolumes onto separate video frames, we can resolve a larger total volume of velocity vectors, while retaining good spatial resolution. We demonstrate this technique by performing time-resolved measurements of the turbulent structure of a round jet, using up to 9 adjacent volume slices. In essence this technique resolves more velocity planes in the depth direction by maintaining optimal particle image density and limiting the number of ghost particles. The total measurement volumes contain between 1 ×106 and 3 ×106 velocity vectors calculated from up to 1500 reconstructed depthwise image planes, showing time-resolved evolution of the large-scale vortical structures for a turbulent jet of Re up to 10 000.

  6. Applying galactic archeology to massive galaxies using deep imaging surveys

    CERN Document Server

    Duc, Pierre-Alain

    2014-01-01

    Various programs aimed at exploring the still largely unknown low surface brightness Universe with deep imaging optical surveys have recently started. They open a new window for studies of galaxy evolution, pushing the technique of galactic archeology outside the Local Group (LG). The method, based on the detection and analysis of the diffuse light emitted by collisional debris or extended stellar halos (rather than on stellar counts as done for LG systems), faces however a number of technical difficulties, like the contamination of the images by reflection halos and Galactic cirrus. I review here the on-going efforts to address them and highlight the preliminary promising results obtained with a systematic survey with MegaCam on the CFHT of nearby massive early-type galaxies done as part of the Atlas3D, NGVS and MATLAS collaborations.

  7. Free Radical Imaging Techniques Applied to Hydrocarbon Flames Diagnosis

    Institute of Scientific and Technical Information of China (English)

    A. Caldeira-Pires

    2001-01-01

    This paper evaluates the utilization of free radical chemiluminescence imaging and tomographic reconstruction techniques to assess advanced information on reacting flows. Two different laboratory flow configurations were analyzed, including unconfined non-premixed jet flame measurements to evaluate flame fuel/air mixing patterns at the burner-port of a typical glass-furnace burner. The second case characterized the reaction zone of premixed flames within gas turbine combustion chambers, based on a laboratory scale model of a lean prevaporized premixed (LPP) combustion chamber.The analysis shows that advanced imaging diagnosis can provide new information on the characterization of flame mixing and reacting phenomena. The utilization of local C2 and CH chemiluminescence can assess useful information on the quality of the combustion process, which can be used to improve the design of practical combustors.

  8. Atlantoaxial subluxation. Radiography and magnetic resonance imaging correlated to myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Y.; Takahashi, M.; Sakamoto, Y.; Kojima, R.

    Twenty-nine patients with atlantoaxial subluxation (18 with rheumatoid arthritis, 2 due to trauma, 4 with os odontoideum, and one each with polyarteritis nodosa, rheumatic fever, Klippel-Feil syndrome, achondroplasia, and cause unknown) were evaluated using a 0.22 tesla resistive MRI unit. Cord compression was classified into four grades according to the degree on magnetic resonance imaging. There were 7 patients with no thecal sac compression (grade 0), 10 with a minimal degree of subarachnoid space compression without cord compression (grade 1), 7 with mild cord compression (grade 2), and 5 with severe cord compression or cord atrophy (grade 3). Although the severity of myelopathy showed poor correlation with the atlantodental interval on conventional radiography, high correlation was observed between MR grading and the degree of myelopathy. The high signal intensity foci were observed in 7 or 12 patients with cord compression (grades 2 and 3) on T2 weighted images. Other frequently observed findings in rheumatoid arthritis included soft tissue masses of low to intermediate signal intensity in the paraodontoid space, erosions of the odontoid processes, and atlanto-axial impaction on T1 and T2 weighted images.

  9. Dynamic Approaches for Facial Recognition Using Digital Image Speckle Correlation

    Science.gov (United States)

    Rafailovich-Sokolov, Sara; Guan, E.; Afriat, Isablle; Rafailovich, Miriam; Sokolov, Jonathan; Clark, Richard

    2004-03-01

    Digital image analysis techniques have been extensively used in facial recognition. To date, most static facial characterization techniques, which are usually based on Fourier transform techniques, are sensitive to lighting, shadows, or modification of appearance by makeup, natural aging or surgery. In this study we have demonstrated that it is possible to uniquely identify faces by analyzing the natural motion of facial features with Digital Image Speckle Correlation (DISC). Human skin has a natural pattern produced by the texture of the skin pores, which is easily visible with conventional digital cameras of resolution greater than 4 mega pixels. Hence the application of the DISC method to the analysis of facial motion appears to be very straightforward. Here we demonstrate that the vector diagrams produced by this method for facial images are directly correlated to the underlying muscle structure which is unique for an individual and is not affected by lighting or make-up. Furthermore, we will show that this method can also be used for medical diagnosis in early detection of facial paralysis and other forms of skin disorders.

  10. A new deconvolution approach to perfusion imaging exploiting spatial correlation

    Science.gov (United States)

    Orten, Burkay B.; Karl, W. Clem; Sahani, Dushyant V.; Pien, Homer

    2008-03-01

    The parts of the human body affected by a disease do not only undergo structural changes but also demonstrate significant physiological (functional) abnormalities. An important parameter that reveals the functional state of tissue is the flow of blood per unit tissue volume or perfusion, which can be obtained using dynamic imaging methods. One mathematical approach widely used for estimating perfusion from dynamic imaging data is based on a convolutional tissue-flow model. In these approaches, deconvolution of the observed data is necessary to obtain the important physiological parameters within a voxel. Although several alternatives have been proposed for deconvolution, all of them treat neighboring voxels independently and do not exploit the spatial correlation between voxels or the temporal correlation within a voxel over time. These simplistic approaches result in a noisy perfusion map with poorly defined region boundaries. In this paper, we propose a novel perfusion estimation method which incorporates spatial as well as temporal correlation into the deconvolution process. Performance of our method is compared to standard methods using independent voxel processing. Both simulated and real data experiments illustrate the potential of our method.

  11. State-correlated DC slice imaging of formaldehyde photodissociation

    Science.gov (United States)

    Suits, Arthur G.; Chambreau, Steven D.; Lahankar, Sridhar A.

    High-resolution slice imaging methods allow for detection of single product quantum states with sufficient velocity resolution to infer the full correlated product state distribution of the undetected fragment. This is a level of detail not available in previous studies of formaldehyde photodissociation, and in this application it reveals startling new aspects of unimolecular decomposition. The CO rotational distributions from near ultraviolet dissociation of formaldehyde are bimodal, and the imaging experiments allow us to decompose these into two dynamically distinct components: the conventional molecular dissociation over a high exit barrier, and a novel `roaming atom' reaction in which frustrated radical dissociation events lead to intramolecular H abstraction, bypassing the transition state entirely. In probing the dynamics of the conventional molecular dissociation over the barrier, we use the complete vH2-jCO correlation to model the exit channel dynamics in new detail. Furthermore, these state-correlated measurements provide insight into radical-radical reactions and the underlying dynamics and energy dependence of the roaming pathway.

  12. Multilabel image classification via high-order label correlation driven active learning.

    Science.gov (United States)

    Zhang, Bang; Wang, Yang; Chen, Fang

    2014-03-01

    Supervised machine learning techniques have been applied to multilabel image classification problems with tremendous success. Despite disparate learning mechanisms, their performances heavily rely on the quality of training images. However, the acquisition of training images requires significant efforts from human annotators. This hinders the applications of supervised learning techniques to large scale problems. In this paper, we propose a high-order label correlation driven active learning (HoAL) approach that allows the iterative learning algorithm itself to select the informative example-label pairs from which it learns so as to learn an accurate classifier with less annotation efforts. Four crucial issues are considered by the proposed HoAL: 1) unlike binary cases, the selection granularity for multilabel active learning need to be fined from example to example-label pair; 2) different labels are seldom independent, and label correlations provide critical information for efficient learning; 3) in addition to pair-wise label correlations, high-order label correlations are also informative for multilabel active learning; and 4) since the number of label combinations increases exponentially with respect to the number of labels, an efficient mining method is required to discover informative label correlations. The proposed approach is tested on public data sets, and the empirical results demonstrate its effectiveness.

  13. Image analysis technique applied to lock-exchange gravity currents

    OpenAIRE

    Nogueira, Helena; Adduce, Claudia; Alves, Elsa; Franca, Rodrigues Pereira Da; Jorge, Mario

    2013-01-01

    An image analysis technique is used to estimate the two-dimensional instantaneous density field of unsteady gravity currents produced by full-depth lock-release of saline water. An experiment reproducing a gravity current was performed in a 3.0 m long, 0.20 m wide and 0.30 m deep Perspex flume with horizontal smooth bed and recorded with a 25 Hz CCD video camera under controlled light conditions. Using dye concentration as a tracer, a calibration procedure was established for each pixel in th...

  14. Event-based image recognition applied in tennis training assistance

    Science.gov (United States)

    Wawrzyniak, Zbigniew M.; Kowalski, Adam

    2016-09-01

    This paper presents a concept of a real-time system for individual tennis training assistance. The system is supposed to provide user (player) with information on his strokes accuracy as well as other training quality parameters such as velocity and rotation of the ball during its flight. The method is based on image processing methods equipped with developed explorative analysis of the events and their description by parameters of the movement. There has been presented the concept for further deployment to create a complete system that could assist tennis player during individual training.

  15. Precision Improvement of Photogrammetry by Digital Image Correlation

    Science.gov (United States)

    Shih, Ming-Hsiang; Sung, Wen-Pei; Tung, Shih-Heng; Hsiao, Hanwei

    2016-04-01

    The combination of aerial triangulation technology and unmanned aerial vehicle greatly reduces the cost and application threshold of the digital surface model technique. Based on the report in the literatures, the measurement error in the x-y coordinate and in the elevation lies between 8cm~15cm and 10cm~20cm respectively. The measurement accuracy for the geological structure survey already has sufficient value, but for the slope and structures in terms of deformation monitoring is inadequate. The main factors affecting the accuracy of the aerial triangulation are image quality, measurement accuracy of control point and image matching accuracy. In terms of image matching, the commonly used techniques are Harris Corner Detection and Scale Invariant Feature Transform (SIFT). Their pairing error is in scale of pixels, usually lies between 1 to 2 pixels. This study suggests that the error on the pairing is the main factor causing the aerial triangulation errors. Therefore, this study proposes the application of Digital Image Correlation (DIC) method instead of the pairing method mentioned above. DIC method can provide a pairing accuracy of less than 0.01 pixel, indeed can greatly enhance the accuracy of the aerial triangulation, to have sub-centimeter level accuracy. In this study, the effects of image pairing error on the measurement error of the 3-dimensional coordinate of the ground points are explored by numerical simulation method. It was confirmed that when the image matching error is reduced to 0.01 pixels, the ground three-dimensional coordinate measurement error can be controlled in mm level. A combination of DIC technique and the traditional aerial triangulation provides the potential of application on the deformation monitoring of slope and structures, and achieve an early warning of natural disaster.

  16. Correlation of live-cell imaging with volume scanning electron microscopy.

    Science.gov (United States)

    Lucas, Miriam S; Günthert, Maja; Bittermann, Anne Greet; de Marco, Alex; Wepf, Roger

    2017-01-01

    Live-cell imaging is one of the most widely applied methods in live science. Here we describe two setups for live-cell imaging, which can easily be combined with volume SEM for correlative studies. The first procedure applies cell culture dishes with a gridded glass support, which can be used for any light microscopy modality. The second approach is a flow-chamber setup based on Ibidi μ-slides. Both live-cell imaging strategies can be followed up with serial blockface- or focused ion beam-scanning electron microscopy. Two types of resin embedding after heavy metal staining and dehydration are presented making best use of the particular advantages of each imaging modality: classical en-bloc embedding and thin-layer plastification. The latter can be used only for focused ion beam-scanning electron microscopy, but is advantageous for studying cell-interactions with specific substrates, or when the substrate cannot be removed. En-bloc embedding has diverse applications and can be applied for both described volume scanning electron microscopy techniques. Finally, strategies for relocating the cell of interest are discussed for both embedding approaches and in respect to the applied light and scanning electron microscopy methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Correlations between diffusion-weighted imaging and breast cancer biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Martincich, Laura; Deantoni, Veronica; Bertotto, Ilaria; Liotti, Michele; Regge, Daniele [Unit of Radiology, Institute for Cancer Research and Treatment (IRCC), Candiolo, Turin (Italy); Redana, Stefania; Rossi, Valentina; Aglietta, Massimo; Montemurro, Filippo [Institute for Cancer Research and Treatment (IRCC), Division of Medical Oncology, Candiolo, Turin (Italy); Kubatzki, Franziska; Ponzone, Riccardo [Institute for Cancer Research and Treatment (IRCC), Division of Gynecological Oncology, Candiolo, Turin (Italy); Sarotto, Ivana [Unit of Pathology, Institute for Cancer Research and Treatment (IRCC), Candiolo, Turin (Italy)

    2012-07-15

    We evaluated whether the apparent diffusion coefficient (ADC) provided by diffusion-weighted imaging (DWI) varies according to biological features in breast cancer. DWI was performed in 190 patients undergoing dynamic contrast-enhanced magnetic resonance imaging (MRI) for local staging. For each of the 192 index cancers we studied the correlation between ADC and classical histopathological and immunohistochemical breast tumour features (size, histological type, grade, oestrogen receptor [ER] and Ki-67 expression, HER2 status). ADC was compared with immunohistochemical surrogates of the intrinsic subtypes (Luminal A; Luminal B; HER2-enriched; triple-negative). Correlations were analysed using the Mann-Whitney U and Kruskal-Wallis H tests. A weak, statistically significant correlation was observed between ADC values and the percentage of ER-positive cells (-0.168, P = 0.020). Median ADC values were significantly higher in ER-negative than in ER-positive tumours (1.110 vs 1.050 x 10{sup -3} mm{sup 2}/s, P = 0.015). HER2-enriched tumours had the highest median ADC value (1.190 x 10{sup -3} mm{sup 2}/s, range 0.950-2.090). Multiple comparisons showed that this value was significantly higher than that of Luminal A (1.025 x 10{sup -3} mm{sup 2}/s [0.700-1.340], P = 0.004) and Luminal B/HER2-negative (1.060 x 10{sup -3} mm{sup 2}/s [0.470-2.420], P = 0.008) tumours. A trend towards statistical significance (P = 0.018) was seen with Luminal B/HER2-positive tumours. ADC values vary significantly according to biological tumour features, suggesting that cancer heterogeneity influences imaging parameters. (orig.)

  18. Feature selection applied to ultrasound carotid images segmentation.

    Science.gov (United States)

    Rosati, Samanta; Molinari, Filippo; Balestra, Gabriella

    2011-01-01

    The automated tracing of the carotid layers on ultrasound images is complicated by noise, different morphology and pathology of the carotid artery. In this study we benchmarked four methods for feature selection on a set of variables extracted from ultrasound carotid images. The main goal was to select those parameters containing the highest amount of information useful to classify the pixels in the carotid regions they belong to. Six different classes of pixels were identified: lumen, lumen-intima interface, intima-media complex, media-adventitia interface, adventitia and adventitia far boundary. The performances of QuickReduct Algorithm (QRA), Entropy-Based Algorithm (EBR), Improved QuickReduct Algorithm (IQRA) and Genetic Algorithm (GA) were compared using Artificial Neural Networks (ANNs). All methods returned subsets with a high dependency degree, even if the average classification accuracy was about 50%. Among all classes, the best results were obtained for the lumen. Overall, the four methods for feature selection assessed in this study return comparable results. Despite the need for accuracy improvement, this study could be useful to build a pre-classifier stage for the optimization of segmentation performance in ultrasound automated carotid segmentation.

  19. Novel rangefinding system using a correlation image sensor

    Science.gov (United States)

    Kimachi, Akira; Kurihara, Toru; Takamoto, Masao; Ando, Shigeru

    2000-12-01

    This paper proposes a 3D measurement principle for the correlation image sensor (CIS), which generates temporal correlation between light intensity and an external reference signal at each pixel. Another key of our system besides the CIS is amplitude-modulation of the scanning sheet beam, the phase of which relative to a reference signal is varied according to the scanning angle. After a scan within a frame, the phase is demodulated with a quadrature pair of reference signals and output by the CIS to compute the individual angle of the sheet bam at each pixel. By virtue of lock-in detection principle, the effects of background illumination and/or surface reflectance nonuniformity of the object are thoroughly removed. We implemented this system using our CMOS 64 by 64 pixel CIS, and successfully reconstructed a depth map under its frame rate.

  20. Full-field digital image correlation with Kriging regression

    Science.gov (United States)

    Wang, Dezhi; DiazDelaO, F. A.; Wang, Weizhuo; Mottershead, John E.

    2015-04-01

    A full-field Digital Image Correlation (DIC) method with integrated Kriging regression is presented in this article. The displacement field is formulated as a best linear unbiased model that includes the correlations between all the locations in the Region of Interest (RoI). A global error factor is employed to extend conventional Kriging interpolation to quantify displacement errors of the control points. An updating strategy for the self-adaptive control grid is developed on the basis of the Mean Squared Error (MSE) determined from the Kriging model. Kriging DIC is shown to outperform several other full-field DIC methods when using open-access experimental data. Numerical examples are used to demonstrate the robustness of Kriging DIC to different choices of initial control points and to speckle pattern variability. Finally Kriging DIC is tested on an experimental example.

  1. Multimodal imaging in cerebral gliomas and its neuropathological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Gempt, Jens, E-mail: jens.gempt@lrz.tum.de [Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); Soehngen, Eric [Abteilung für Neuroradiologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); Abteilung für Neuropathologie des Instituts für Allgemeine Pathologie und Pathologische Anatomie, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); Förster, Stefan [Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); Ryang, Yu-Mi [Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); Schlegel, Jürgen [Abteilung für Neuropathologie des Instituts für Allgemeine Pathologie und Pathologische Anatomie, Technische Universität München, Ismaninger Str. 22, 81675 München (Germany); and others

    2014-05-15

    Introduction: Concerning the preoperative clinical diagnostic work-up of glioma patients, tumor heterogeneity challenges the oncological therapy. The current study assesses the performance of a multimodal imaging approach to differentiate between areas in malignant gliomas and to investigate the extent to which such a combinatorial imaging approach might predict the underlying histology. Methods: Prior to surgical resection, patients harboring intracranial gliomas underwent MRIs (MR-S, PWI) and {sup 18}F-FET-PETs. Intratumoral and peritumoral biopsy targets were defined, by MRI only, by FET-PET only, and by MRI and FET-PET combined, and biopsied prior to surgical resection and which then received separate histopathological examinations. Results: In total, 38 tissue samples were acquired (seven glioblastomas, one anaplastic astrocytoma, one anaplastic oligoastrocytoma, one diffuse astrocytoma, and one oligoastrocytoma) and underwent histopathological analysis. The highest mean values of Mib1 and CD31 were found in the target point “T’ defined by MRI and FET-PET combined. A significant correlation between NAA/Cr and PET tracer uptake (−0.845, p < 0.05) as well as Cho/Cr ratio and cell density (0.742, p < 0.05) and NAA/Cr ratio and MIB-1 (−0761, p < 0.05) was disclosed for this target point, though not for target points defined by MRI and FET-PET alone. Conclusion: Multimodal-imaging-guided stereotactic biopsy correlated more with histological malignancy indices, such as cell density and MIB-1 labeling, than targets that were based solely on the highest amino acid uptake or contrast enhancement on MRI. The results of our study indicate that a combined PET-MR multimodal imaging approach bears potential benefits in detecting glioma heterogeneity.

  2. Automated microaneurysm detection algorithms applied to diabetic retinopathy retinal images

    Directory of Open Access Journals (Sweden)

    Akara Sopharak

    2013-07-01

    Full Text Available Diabetic retinopathy is the commonest cause of blindness in working age people. It is characterised and graded by the development of retinal microaneurysms, haemorrhages and exudates. The damage caused by diabetic retinopathy can be prevented if it is treated in its early stages. Therefore, automated early detection can limit the severity of the disease, improve the follow-up management of diabetic patients and assist ophthalmologists in investigating and treating the disease more efficiently. This review focuses on microaneurysm detection as the earliest clinically localised characteristic of diabetic retinopathy, a frequently observed complication in both Type 1 and Type 2 diabetes. Algorithms used for microaneurysm detection from retinal images are reviewed. A number of features used to extract microaneurysm are summarised. Furthermore, a comparative analysis of reported methods used to automatically detect microaneurysms is presented and discussed. The performance of methods and their complexity are also discussed.

  3. Stereo particle image velocimetry applied to a vortex pipe flow

    Science.gov (United States)

    Zhang, Zherui; Hugo, Ronald J.

    2006-03-01

    Stereo particle image velocimetry (PIV) has been employed to study a vortex generated via tangential injection of water in a 2.25 inch (57 mm) diameter pipe for Reynolds numbers ranging from 1,118 to 63,367. Methods of decreasing pipe-induced optical distortion and the PIV calibration technique are addressed. The mean velocity field analyses have shown spatial similarity and revealed four distinct flow regions starting from the central axis of rotation to the pipe wall in the vortex flows. Turbulence statistical data and vortex core location data suggest that velocity fluctuations are due to the axis of the in-line vortex distorting in the shape of a spiral.

  4. Multi-scale crack closure measurements with digital image correlation on Haynes 230

    Directory of Open Access Journals (Sweden)

    Stefano Beretta

    2015-07-01

    Full Text Available An experimental campaign was developed to study fatigue crack growth in Haynes 230, a Ni-based superalloy. The effects of crack closure were investigated with digital image correlation, by applying two different approaches. Initially, full field regression algorithms were applied to extract the effective stress intensity factor ranges from the singular displacement field measured at crack tips. Local closure measurements were then performed by considering crack flanks relative displacements. Two points virtual extensometers were applied in this phase. Experimental results were then compared to the reference da/dN –ΔKeff curve: it was found that the correct estimation of crack opening levels shifts all the experimental points on the reference curve, showing that DIC can be successfully applied to measure crack closure effects.

  5. Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.

    Directory of Open Access Journals (Sweden)

    Michael U Gutmann

    Full Text Available Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.

  6. Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.

    Science.gov (United States)

    Gutmann, Michael U; Laparra, Valero; Hyvärinen, Aapo; Malo, Jesús

    2014-01-01

    Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified) statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.

  7. Electron Correlation Microscopy: A New Technique for Studying Local Atom Dynamics Applied to a Supercooled Liquid.

    Science.gov (United States)

    He, Li; Zhang, Pei; Besser, Matthew F; Kramer, Matthew Joseph; Voyles, Paul M

    2015-08-01

    Electron correlation microscopy (ECM) is a new technique that utilizes time-resolved coherent electron nanodiffraction to study dynamic atomic rearrangements in materials. It is the electron scattering equivalent of photon correlation spectroscopy with the added advantage of nanometer-scale spatial resolution. We have applied ECM to a Pd40Ni40P20 metallic glass, heated inside a scanning transmission electron microscope into a supercooled liquid to measure the structural relaxation time τ between the glass transition temperature T g and the crystallization temperature, T x . τ determined from the mean diffraction intensity autocorrelation function g 2(t) decreases with temperature following an Arrhenius relationship between T g and T g +25 K, and then increases as temperature approaches T x . The distribution of τ determined from the g 2(t) of single speckles is broad and changes significantly with temperature.

  8. Correlating Function and Imaging Measures of the Medial Longitudinal Fasciculus.

    Directory of Open Access Journals (Sweden)

    Ken Sakaie

    Full Text Available To test the validity of diffusion tensor imaging (DTI measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF. Injury to the MLF underlies internuclear ophthalmoparesis (INO.40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD, transverse diffusivity (TD, mean diffusivity (MD and fractional anisotropy (FA. Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI.LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03. FA was also lower in patients in the same region (p < 0.0004. LD of the medulla-pons region correlated with VDI (R = -0.28, p < 0.05 as did FA in the midbrain section (R = 0.31, p < 0.02.This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity.

  9. Image deblurring applied to infrared tongue position imaging: Initial simulation results

    Science.gov (United States)

    Poots, J. Kent

    2013-10-01

    Paper describes development work for a new biomedical application of image deblurring. Optical imaging is not currently used to assess tongue position during speech, nor is optical imaging the modality of choice for imaging tissue of moderate thickness. Tongue position assessment is important during rehabilitation. Optical imaging of biological tissue provides good contrast, but incident light is scattered, seriously restricting clinical usefulness. Paper describes simulation results for scattering correction and suggests possible directions for future work. Images are represented by sparse matrices.

  10. Remote Imaging Applied to Schistosomiasis Control: The Anning River Project

    Science.gov (United States)

    Seto, Edmund Y. W.; Maszle, Don R.; Spear, Robert C.; Gong, Peng

    1997-01-01

    The use of satellite imaging to remotely detect areas of high risk for transmission of infectious disease is an appealing prospect for large-scale monitoring of these diseases. The detection of large-scale environmental determinants of disease risk, often called landscape epidemiology, has been motivated by several authors (Pavlovsky 1966; Meade et al. 1988). The basic notion is that large-scale factors such as population density, air temperature, hydrological conditions, soil type, and vegetation can determine in a coarse fashion the local conditions contributing to disease vector abundance and human contact with disease agents. These large-scale factors can often be remotely detected by sensors or cameras mounted on satellite or aircraft platforms and can thus be used in a predictive model to mark high risk areas of transmission and to target control or monitoring efforts. A review of satellite technologies for this purpose was recently presented by Washino and Wood (1994) and Hay (1997) and Hay et al. (1997).

  11. Detectability of Pore Defect in Wind Turbine Blade Composites Using Image Correlation Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Il; Huh, Yong Hak; Lee, Gun Chang [Korea Research institute of Standard and Science, Daejeon (Korea, Republic of)

    2013-10-15

    Defects that occur during the manufacturing process or operation of a wind turbine blade have a great influence on its life and safety. Typically, defects such as delamination, pore, wrinkle and matrix crack are found in a blade. In this study, the detectability of the pores, a type of defect that frequently occur during manufacturing, was examined from the full field strain distribution determined with the image correlation technique. Pore defects were artificially introduced in four-ply laminated GFRP composites with 0 .deg/{+-}45 .deg fiber direction. The artificial pores were introduced in consideration of their size and location. Three different-sized pores with diameter of 1, 2 and 3 mm were located on the top and bottom surface and embedded. By applying static loads of 0-200 MPa, the strain distributions over the specimen with the pore defects were determined using image correlation technique. It was found the pores with diameter exceeding 2 mm can be detected in diameter.

  12. Subcutaneous and musculoskeletal sparganosis: imaging characteristics and pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J.-H. [Department of Diagnostic Radiology, Ajou University, College of Medicine, Suwon (Korea)]|[Department of Diagnostic Radiology, Ajou University, Hospital a5 Wonchundong, Paldalgu, Suwon, Kyounggi (Korea); Lee, K.-B. [Department of Pathology, Ajou University, College of Medicine, Suwon (Korea); Yong, T.-S. [Department of Parasitology, Yonsei University, College of Medicine, Seoul (Korea); Kim, B.-S. [Department of Orthopedic Surgery, Ajou University, College of Medicine, Suwon (Korea); Park, H.-B. [Department of General Surgery, Ajou University, College of Medicine, Suwon (Korea); Ryu, K.-N. [Department of Radiology, Kyounghee University, College of Medicine, Seoul (Korea); Park, J. [Department of Radiology, Catholic University, College of Medicine, Seoul (Korea); Lee, S.-Y. [Department of Radiology, Chunnam University, College of Medicine, Jeonju (Korea); Suh, J.-S. [Department of Radiology, Yonsei University, College of Medicine, Seoul (Korea)

    2000-07-01

    Objective. To document the imaging characteristics of subcutaneous and musculoskeletal sparganosis.Design and patients. Ten patients with musculoskeletal sparganosis were examined, with a variety of imaging modalities including MRI (n=6), ultrasonography (n=8), plain radiography (n=7) and CT (n=1). Pathologic correlation was carried out in all cases.Results. Nine lesions involved soft tissues, of which seven were in the thigh, two in the trunk and one involved a vertebral body. The majority of the lesions in soft tissue were confined to the subcutaneous layer but two extended deep into underlying muscles. Sonography revealed low-echoic serpiginous tubular tracts (8/8), and an intraluminal echogenic structure (4/8). MRI revealed multiple serpiginous tubular tracts and peripheral rim enhancement. Two patients showed perilesional soft tissue edema. Pathologically, the lesion consisted of a larva surrounded by three layers of inflammation: an inner epithelioid granulomatous cell layer, middle chronic inflammatory cell layers, and an outer fibrous layer.Conclusion. The study suggests that if serpiginous tubular tracts are seen at imaging studies, musculoskeletal sparganosis should be included in the differential diagnosis. (orig.)

  13. Quantum correlated cluster mean-field theory applied to the transverse Ising model.

    Science.gov (United States)

    Zimmer, F M; Schmidt, M; Maziero, Jonas

    2016-06-01

    Mean-field theory (MFT) is one of the main available tools for analytical calculations entailed in investigations regarding many-body systems. Recently, there has been a surge of interest in ameliorating this kind of method, mainly with the aim of incorporating geometric and correlation properties of these systems. The correlated cluster MFT (CCMFT) is an improvement that succeeded quite well in doing that for classical spin systems. Nevertheless, even the CCMFT presents some deficiencies when applied to quantum systems. In this article, we address this issue by proposing the quantum CCMFT (QCCMFT), which, in contrast to its former approach, uses general quantum states in its self-consistent mean-field equations. We apply the introduced QCCMFT to the transverse Ising model in honeycomb, square, and simple cubic lattices and obtain fairly good results both for the Curie temperature of thermal phase transition and for the critical field of quantum phase transition. Actually, our results match those obtained via exact solutions, series expansions or Monte Carlo simulations.

  14. Interest of correlation-based automatic target recognition in underwater optical images: theoretical justification and first results

    Science.gov (United States)

    Leonard, I.; Arnold-Bos, A.; Alfalou, A.

    2010-04-01

    In this paper, we explore the use of optical correlation-based recognition to identify and position underwater man-made objects (e.g. mines). Correlation techniques can be defined as a simple comparison between an observed image (image to recognize) and a reference image; they can be achieved extremely fast. The result of this comparison is a more or less intense correlation peak, depending on the resemblance degree between the observed image and a reference image coming from a database. However, to perform a good correlation decision, we should compare our observed image with a huge database of references, covering all the appearances of objects we search. Introducing all the appearances of objects can influence speed and/or recognition quality. To overcome this limitation, we propose to use composite filter techniques, which allow the fusion of several references and drastically reduce the number of needed comparisons to identify observed images. These recent techniques have not yet been exploited in the underwater context. In addition, they allow for integrating some preprocessing directly in the correlation filter manufacturing step to enhance the visibility of objects. Applying all the preprocessing in one step reduces the processing by avoiding unnecessary Fourier transforms and their inverse operation. We want to obtain filters that are independent from all noises and contrast problems found in underwater videos. To achieve this and to create a database containing all scales and viewpoints, we use as references 3D computer-generated images.

  15. Full-field Measurement of Deformation and Vibration using Digital Image Correlation

    Directory of Open Access Journals (Sweden)

    Liang-Chih Chen

    2015-05-01

    Full Text Available The main intention of this study was to investigate the full-field measurement of de-formation and vibration using a program we developed for digital image correlation. Digital image correlation is a measuring method that can calculate the displacement of each point on an object by using recorded images. By capturing continuous images of the object in deformation or in motion, the displacements of feature points on the object can be tracked and used in calculations to determine the full-field deformation, strain and vibration of the object. We used the fast and simple algorithm in our program as the core, and conducted non-contact full-field displacement measurement by tracking feature points from images taken after motion. The measuring accuracy can be up to 0.1 pixel. Our experimental results show the technique to be very accurate and useful. We also applied this technique under conditions where an ordinary sensor could not be used.

  16. Exploring the limits of waveform correlation event detection as applied to three earthquake aftershock sequences.

    Energy Technology Data Exchange (ETDEWEB)

    Resor, Megan E.; Carr, Dorthe Bame; Young, Christopher John

    2010-05-01

    addition, the Waveform Correlation Detector and Self Scanner identified significant numbers of new events that were not in either the EDR or regional catalogs, showing a lowering of the detection threshold. We extended our analysis to study the effect of distance on correlation results by applying the analysis tools to multiple stations along a transect of nearly constant azimuth when possible. We expected the number of events found via correlation would drop off as roughly 1/r2, where r is the distance from mainshock to station. However, we found that regional geological conditions influenced the performance of a given station more than distance. For example, for one sequence we clustered 25% of events at the nearest station to the mainshock (34 km), while our performance dropped to 2% at a station 550 km distant. However, we matched our best performance (25% clustering) at a station 198 km distant.

  17. Summary of the Nevada Applied Ecology Group and correlative programs. Version 1

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, H.N. [Raytheon Services Nevada, Las Vegas, NV (United States)

    1992-10-01

    This summary document presents results in a broad context; it is not limited to findings of the Nevada Applied Ecology Group. This book is organized to present the findings of the Nevada Applied Ecology Group and correlative programs in accordance with the originally stated objectives of the Nevada Applied Ecology Group. This plan, in essence, traces plutonium from its injection into the environment to movement in the ecosystem to development of cleanup techniques. Information on other radionuclides was also obtained and will be presented briefly. Chapter 1 presents a brief description of the ecological setting of the Test Range Complex. The results of investigations for plutonium distribution are presented in Chapter 2 for the area surrounding the Test Range Complex and in Chapter 3 for on-site locations. Chapters 4 and 5 present the results of investigations concerned with concentrations and movement, respectively, of plutonium in the ecosystem of the Test Range Complex, and Chapter 6 summarizes the potential hazard from this plutonium. Development of techniques for cleanup and treatment is presented in Chapter 7, and the inventory of radionuclides other than plutonium is presented briefly in Chapter 8.

  18. Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting.

    Directory of Open Access Journals (Sweden)

    Sarah L Veatch

    Full Text Available We present an analytical method using correlation functions to quantify clustering in super-resolution fluorescence localization images and electron microscopy images of static surfaces in two dimensions. We use this method to quantify how over-counting of labeled molecules contributes to apparent self-clustering and to calculate the effective lateral resolution of an image. This treatment applies to distributions of proteins and lipids in cell membranes, where there is significant interest in using electron microscopy and super-resolution fluorescence localization techniques to probe membrane heterogeneity. When images are quantified using pair auto-correlation functions, the magnitude of apparent clustering arising from over-counting varies inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. In contrast, we demonstrate that over-counting does not give rise to apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (FcεRI on the plasma membranes of chemically fixed RBL-2H3 mast cells from images acquired using stochastic optical reconstruction microscopy (STORM/dSTORM and scanning electron microscopy (SEM. We find that apparent clustering of FcεRI-bound IgE is dominated by over-counting labels on individual complexes when IgE is directly conjugated to organic fluorophores. We verify this observation by measuring pair cross-correlation functions between two distinguishably labeled pools of IgE-FcεRI on the cell surface using both imaging methods. After correcting for over-counting, we observe weak but significant self-clustering of IgE-FcεRI in fluorescence localization measurements, and no residual self-clustering as detected with SEM. We also apply this method to quantify IgE-FcεRI redistribution after deliberate clustering by

  19. Imaging of compound palmar ganglion with pathologic correlation

    Directory of Open Access Journals (Sweden)

    Sourav Talukder

    2014-04-01

    Full Text Available Compound palmar ganglion, or chronic flexor tenosynovitis, most commonly of tuberculousorigin, is a rare extrapulmonary manifestation of tuberculosis (TB. The flexor synovialsheath is not a common site for TB but, once involved, causes rapid involvement of all flexortendons. We discuss the case of a 70-year-old farmer who presented to us with pain and progressive swelling of the palmar aspect of the wrist. On clinical examination, swelling both above and below the proximal wrist crease was found, with positive cross-fluctuation. Onultrasonography and magnetic resonance imaging, features suggestive of compound palmarganglion were present. The patient underwent surgical resection (extensive tenosynovectomyand chemotherapy. Post-operative histopatholgical findings correlated with the radiological features.

  20. Identification of the plastic zone using digital image correlation

    Directory of Open Access Journals (Sweden)

    M. Rossi

    2014-10-01

    Full Text Available In this paper Digital Image Correlation (DIC is used to study the evolution of the plastic zone close to a crack tip. A modified CT-specimen was used in order to fulfill the plane stress condition. The strain field around the crack tip was measured using two cameras and stereo DIC, so that out-of-plane movements are taken into account. Then, the Virtual Fields Method was used to identify the plastic zone, looking at the parts of the specimen which deviates from the linear elastic behavior. With such approach, it was possible to individuate the onset of plasticity close to the crack tip and follow its evolution. A comparison with FEM results is also provided.

  1. Posterolateral Complex Knee Injuries: Magnetic Resonance Imaging with Surgical Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Theodorou, D.J. [Univ. of California, San Diego, CA (United States). Dept. of Radiology; Theodorou, S.J.; Fithian, D.C.; Garelick, D.H. [Southern California Permanente Medical Group, San Diego, CA (United States). Dept. of Orthopedic Surgery; Paxton, L.; Resnick, D. [Midwest Orthopedics, Chicago, IL (United States)

    2005-05-01

    Purpose: To describe the magnetic resonance imaging (MRI) findings of injuries of the posterolateral aspect of the knee and to evaluate the diagnostic capabilities of MRI in the assessment of these injuries. Material and Methods: The MRI studies of 14 patients (mean age 33 years) with trauma to the posterolateral aspect of the knee were retrospectively reviewed, and the imaging findings were correlated with those of surgery. Results: In all patients, MRI showed an intact iliotibial (ITB) band. MRI showed injury to the biceps tendon in 11 (79%), the gastrocnemius tendon in (7%), the popliteus tendon in 5 (36%), and the lateral collateral ligament (LCL) in 14 (100%) patients. Tear of the anterior cruciate ligament (ACL) was seen in1 (79%) patients and tear of the posterior cruciate ligament (PCL) in 4 (29%) patients. With routine MRI, visualization of the popliteofibular or fabellofibular ligaments was incomplete. On MRI, the lateral meniscus and the medial meniscus were torn with equal frequency ( n {approx} 4; 29%). Osteochondral defects were seen in 5 (36%) cases and joint effusion in all 14 (100%) cases on MRI. Using surgical findings as the standard for diagnosis, MRI proved 86% accurate in the detection of injury to the ITB band, the biceps tendon (93%),, the gastrocnemius tendon (100%), the popliteus tendon (86%), the LCL (100%), the ACL (79%), the PCL (86%), the lateral meniscus (90%), the medial meniscus (82%), and the osteochondral structures (79%). Surgical correlation confirmed the MRI findings of joint effusion in all cases. Conclusion: MRI is well suited for demonstrating the presence and extent of injuries of the major structures of the posterolateral complex of the knee, allowing characterization of the severity of injury.

  2. Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting

    CERN Document Server

    Veatch, Sarah; Shelby, Sarah; Chiang, Ethan; Holowka, David; Baird, Barbara

    2011-01-01

    We present an analytical method to quantify clustering in super-resolution localization images of static surfaces in two dimensions. The method also describes how over-counting of labeled molecules contributes to apparent self-clustering and how the effective lateral resolution of an image can be determined. This treatment applies to clustering of proteins and lipids in membranes, where there is significant interest in using super-resolution localization techniques to probe membrane heterogeneity. When images are quantified using pair correlation functions, the magnitude of apparent clustering due to over-counting will vary inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. Over-counting does not yield apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (Fc{\\epsilon}RI) on the plasma membranes of chemi...

  3. Identification of viscoplastic parameters and characterization of Lüders behaviour using digital image correlation and the virtual fields method

    OpenAIRE

    Avril, Stéphane; Pierron, Fabrice; Sutton, Michael A.; Yan, Junhui

    2008-01-01

    In this study, tensile loading experiments are performed on notched steel bars at an average applied strain rate of 1s-1. Displacement fields are measured across the specimen by coupling digital image correlation (DIC) with imaging using high speed CCD cameras (4796 fps). Results from the experiments indicate the presence of local strain rates ranging from 0.1 to 10s-1 in the notched specimens. The heterogeneity of the strain rate fields provides suitable conditions for determining simultaneo...

  4. A fast digital image correlation method for deformation measurement

    Science.gov (United States)

    Pan, Bing; Li, Kai

    2011-07-01

    Fast and high-accuracy deformation analysis using digital image correlation (DIC) has been increasingly important and highly demanded in recent years. In literature, the DIC method using the Newton-Rapshon (NR) algorithm has been considered as a gold standard for accurate sub-pixel displacement tracking, as it is insensitive to the relative deformation and rotation of the target subset and thus provides highest sub-pixel registration accuracy and widest applicability. A significant drawback of conventional NR-algorithm-based DIC method, however, is its extremely huge computational expense. In this paper, a fast DIC method is proposed deformation measurement by effectively eliminating the repeating redundant calculations involved in the conventional NR-algorithm-based DIC method. Specifically, a reliability-guided displacement scanning strategy is employed to avoid time-consuming integer-pixel displacement searching for each calculation point, and a pre-computed global interpolation coefficient look-up table is utilized to entirely eliminate repetitive interpolation calculation at sub-pixel locations. With these two approaches, the proposed fast DIC method substantially increases the calculation efficiency of the traditional NR-algorithm-based DIC method. The performance of proposed fast DIC method is carefully tested on real experimental images using various calculation parameters. Results reveal that the computational speed of the present fast DIC is about 120-200 times faster than that of the traditional method, without any loss of its measurement accuracy

  5. Applications of three-dimensional image correlation in conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Van Herk, M.; Gilhuijs, K.; Kwa, S.; Lebesque, J.; Muller, S.; De Munck, J.; Touw, A. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands); Kooy, H. [Harvard Medical School, Boston, MA (United States)

    1995-12-01

    The development of techniques for the registration of CT, MRI and SPECT creates new possibilities for improved target volume definition and quantitative image analysis. The discussed technique is based on chamfer matching and is suitable for automatic 3-D matching of CT with CT, CT with MRI, CT with SPECT and MRI with SPECT. By integrating CT with MRI, the diagnostic qualities of MRI are combined with the geometric accuracy of the planning CT. Significant differences in the delineation of the target volume for brain, head and neck and prostate tumors were demonstrated when using integrated CT and MRI compared with using CT alone. In addition, integration of the planning CT with pre-operative scans improves knowledge of possible tumor extents. By first matching scans based on the bony anatomy and subsequently matching on an organ of study, relative motion of the organ is quantified accurately. In a study with 42 CT scans of 11 patients, magnitude and causes of prostate motion were analysed. The most important motion of the prostate is a forward-backward rotation around a point near the apex caused by rectal volume difference. Significant correlations were also found between motion of the legs and the prostate. By integrating functional images made before and after radiotherapy with the planning CT, the relation between local change of lung function and delivered dose has been quantified accurately. The technique of chamfer matching is a convenient and more accurate alternative for the use of external markers in a CT/SPECT lung damage study. Also, damage visible in diagnostic scans can be related to radiation dose, thereby improving follow-up diagnostics. It can be concluded that 3-D image integration plays an important role in assessing and improving the accuracy of radiotherapy and is therefore indispensable for conformal therapy. However, user-friendly implementation of these techniques remains to be done to facilitate clinical application on a large scale.

  6. Correlates of Body Image in Polish Weight Trainers

    Directory of Open Access Journals (Sweden)

    Guszkowska Monika

    2015-06-01

    Full Text Available Purpose. The purpose of this study was to determine body image and body satisfaction in Polish adult men involved in resistance training and to investigate their relationships with objective anthropometric and training characteristics. Methods. The study included 176 males aged 18-31 years with 1-14 years resistance training experience. The Figure Rating Scale, Body Satisfaction Scale and a self-designed questionnaire were administered. Results. Approximately 62% of the participants would like to be more muscular, only 29% accepted their appearance and 9% would like to be less muscular. The body selected as the personal ideal (M = 5.34 was less muscular than the body considered by the participants to be ideal by other men (normative body; M = 6.07 and was more muscular than the body thought to be most attractive to women (M = 5.10. Actual and ideal body muscularity correlated positively with age and body mass, height and BMI. Dissatisfaction with trunk and motor characteristics correlated positively with ideal body and the body considered most attractive to women as well as with the discrepancy indices between the above factors and the actual body. Conclusions. Men regularly involved in resistance training were found to strive for a muscular physique. The normative body, the physique believed to be desired by other men, was more muscular than what was considered preferential to women. However, the latter constitutes a stronger determinant of the level of body satisfaction in men engaged in resistance training.

  7. Human identification using correlation metrics of iris images

    Science.gov (United States)

    Celenk, Mehmet; Brown, Michael; Luo, Yi; Kaufman, Jason; Ma, Limin; Zhou, Qiang

    2005-01-01

    This paper presents work done based on second order statistical features including cross- and auto-correlations as well as co-occurrence matrices of iris images in an attempt to extract a simple, yet powerful, set of features of an iris as a biometric. Prior to our work, the most prevalent methods for iris identification include the frontier work based on the use of quadrature 2-D Gabor wavelets with the Hamming Distance-based classification [1,2], circular Gabor filters with a nearest feature line (NFL) classifier [3], dyadic wavelet transform with the zero-cross detectors [4], texture analysis [9] and transient signal [11], and independent component analysis (ICA) [7], and boundary localization [10]. Our method differs significantly from the earlier approaches to iris recognition in that it relies on the wide-sense stationary approximation to the texture and gray-level characteristics of irises, and aims to lend itself for a single-chip hardware implementation. Our preliminary results show that cross- and auto-correlators along with co-occurrence matrix features are highly likely to be prominent iris discriminators.

  8. Visual masking with frontally applied pre-stimulus TMS and its subject-specific neural correlates.

    Science.gov (United States)

    Rutiku, Renate; Tulver, Kadi; Aru, Jaan; Bachmann, Talis

    2016-07-01

    The visibility of a visual target stimulus depends on the local state of the early visual cortex shortly before the stimulus itself is presented. This view is supported by the observation that occipitally applied pre-stimulus TMS can disrupt subsequent information processing leading to visual masking effects. According to another line of accumulating evidence, however, global pre-stimulus connectivity patterns could be as crucial as local cortical states. In line with the latter view we show that pre-stimulus masking occurs even if TMS is directed to the frontal cortex. Importantly, the individual extent of this effect is strongly correlated with the subject-specific peak latency of a late positive TMS-evoked potential. Our results thus suggest a third type of masking occurring neither through direct interaction with visual areas nor by a modal visual masking input. Our results also shed light on the inter-individual differences in TMS research in general.

  9. Pattern matching and adaptive image segmentation applied to plant reproduction by tissue culture

    Science.gov (United States)

    Vazquez Rueda, Martin G.; Hahn, Federico

    1999-03-01

    This paper shows the results obtained in a system vision applied to plant reproduction by tissue culture using adaptive image segmentation and pattern matching algorithms, this analysis improves the number of tissue obtained and minimize errors, the image features of tissue are considered join to statistical analysis to determine the best match and results. Tests make on potato plants are used to present comparative results with original images processed with adaptive segmentation algorithm and non adaptive algorithms and pattern matching.

  10. Tracking molecular dynamics without tracking: image correlation of photo-activation microscopy

    Science.gov (United States)

    Pandžić, Elvis; Rossy, Jérémie; Gaus, Katharina

    2015-03-01

    Measuring protein dynamics in the plasma membrane can provide insights into the mechanisms of receptor signaling and other cellular functions. To quantify protein dynamics on the single molecule level over the entire cell surface, sophisticated approaches such as single particle tracking (SPT), photo-activation localization microscopy (PALM) and fluctuation-based analysis have been developed. However, analyzing molecular dynamics of fluorescent particles with intermittent excitation and low signal-to-noise ratio present at high densities has remained a challenge. We overcame this problem by applying spatio-temporal image correlation spectroscopy (STICS) analysis to photo-activated (PA) microscopy time series. In order to determine under which imaging conditions this approach is valid, we simulated PA images of diffusing particles in a homogeneous environment and varied photo-activation, reversible blinking and irreversible photo-bleaching rates. Further, we simulated data with high particle densities that populated mobile objects (such as adhesions and vesicles) that often interfere with STICS and fluctuation-based analysis. We demonstrated in experimental measurements that the diffusion coefficient of the epidermal growth factor receptor (EGFR) fused to PAGFP in live COS-7 cells can be determined in the plasma membrane and revealed differences in the time-dependent diffusion maps between wild-type and mutant Lck in activated T cells. In summary, we have developed a new analysis approach for live cell photo-activation microscopy data based on image correlation spectroscopy to quantify the spatio-temporal dynamics of single proteins.

  11. Application of image cross-correlation to the measurement of glacier velocity using satellite image data

    Science.gov (United States)

    Scambos, Theodore A.; Dutkiewicz, Melanie J.; Wison, Jeremy C.; Bindschadler, Robert A.

    1992-01-01

    A high-resolution map of the velocity field of the central portion of Ice Stream E in West Antarctica, generated by the displacement-measuring technique, is presented. The use of cross-correlation software is found to be a significant improvement over previous manually based photogrammetric methods for velocity measurement, and is far more cost-effective than in situ methods in remote polar areas. A hue-intensity-saturation image of Ice Stream E and its velocity field is shown.

  12. Denoising Algorithm for CFA Image Sensors Considering Inter-Channel Correlation.

    Science.gov (United States)

    Lee, Min Seok; Park, Sang Wook; Kang, Moon Gi

    2017-05-28

    In this paper, a spatio-spectral-temporal filter considering an inter-channel correlation is proposed for the denoising of a color filter array (CFA) sequence acquired by CCD/CMOS image sensors. Owing to the alternating under-sampled grid of the CFA pattern, the inter-channel correlation must be considered in the direct denoising process. The proposed filter is applied in the spatial, spectral, and temporal domain, considering the spatio-tempo-spectral correlation. First, nonlocal means (NLM) spatial filtering with patch-based difference (PBD) refinement is performed by considering both the intra-channel correlation and inter-channel correlation to overcome the spatial resolution degradation occurring with the alternating under-sampled pattern. Second, a motion-compensated temporal filter that employs inter-channel correlated motion estimation and compensation is proposed to remove the noise in the temporal domain. Then, a motion adaptive detection value controls the ratio of the spatial filter and the temporal filter. The denoised CFA sequence can thus be obtained without motion artifacts. Experimental results for both simulated and real CFA sequences are presented with visual and numerical comparisons to several state-of-the-art denoising methods combined with a demosaicing method. Experimental results confirmed that the proposed frameworks outperformed the other techniques in terms of the objective criteria and subjective visual perception in CFA sequences.

  13. Application of digital image correlation method for analysing crack variation of reinforced concrete beams

    Indian Academy of Sciences (India)

    Ming-Hsiang Shih; Wen-Pei Sung

    2013-08-01

    The Digital Image Correlation (DIC) method is a fast-growing emerging technology that provides a low-cost method for measuring the strain of an object. In this study, the feasibility of using this method to observe cracks developed in reinforced concrete beams will be explored so that a practical application can be proposed. The DIC method has been applied for analysing the field of surface displacement and strain; it is not applicable for measuring non-continuous field of displacement. However, if a singular point (i.e., crack points) can be considered as the area of concentrated strain by imitating the treatment of micro-cracks using the finite element method, the region of concentrated strain field based on analyses of digital images can be applied for determining the locations of cracks. Laboratory results show that cracks developed in reinforced cement beams can be observed with a good precision using the von Mises strain field, and that smaller grids lead to clearer crack images. In addition to identifying visible cracks, the DIC image analysis will enable researchers to identify minute cracks that are not visible to naked eyes. Additionally, the DIC method has more accuracy and precision than visual observation for analysing crack loadings so that earlier warnings can be realized before cracks develop in the specimen.

  14. High-resolution imaging by scanning electron microscopy of semithin sections in correlation with light microscopy.

    Science.gov (United States)

    Koga, Daisuke; Kusumi, Satoshi; Shodo, Ryusuke; Dan, Yukari; Ushiki, Tatsuo

    2015-12-01

    In this study, we introduce scanning electron microscopy (SEM) of semithin resin sections. In this technique, semithin sections were adhered on glass slides, stained with both uranyl acetate and lead citrate, and observed with a backscattered electron detector at a low accelerating voltage. As the specimens are stained in the same manner as conventional transmission electron microscopy (TEM), the contrast of SEM images of semithin sections was similar to TEM images of ultrathin sections. Using this technique, wide areas of semithin sections were also observed by SEM, without the obstruction of grids, which was inevitable for traditional TEM. This study also applied semithin section SEM to correlative light and electron microscopy. Correlative immunofluorescence microscopy and immune-SEM were performed in semithin sections of LR white resin-embedded specimens using a FluoroNanogold-labeled secondary antibody. Because LR white resin is hydrophilic and electron stable, this resin is suitable for immunostaining and SEM observation. Using correlative microscopy, the precise localization of the primary antibody was demonstrated by fluorescence microscopy and SEM. This method has great potential for studies examining the precise localization of molecules, including Golgi- and ER-associated proteins, in correlation with LM and SEM.

  15. Radar-Interferometric Asteroid Imaging Using a Flexible Software Correlator

    Science.gov (United States)

    Black, G.; Campbell, D. B.; Treacy, R.; Nolan, M. C.

    2005-12-01

    We've developed a technique to use a radio interferometer to image near earth objects (NEOs) during their close Earth approach when they can be illuminated by a ground-based radar system. There is great potential for this technique to yield detailed information that is complementary to other observational methods. We are using the NAIC's Arecibo Observatory's 1 MW 13 cm radar transmitter with the NRAO's Very Long Baseline Array (VLBA) as the receiving instrument. The VLBA, with antenna spacings of several thousands of kilometers, has a potential resolution on the order of milli-arcseconds; a couple of orders of magnitude smaller than typical ground-based telescopic observations, and sufficient to determine the gross shapes and orientations of spin vectors. Milli-arcsecond astrometry of these quickly moving objects can greatly improve their orbits and extend the span over which future Earth encounters can be predicted. The VLBA hardware correlator limits the frequency resolution and complicates incorporating a model of the near-field geometry. Typical target bandwidths are ˜1 Hz while the correlator's narrowest resolution is 120 Hz. To avoid these difficulties a specialized computer interface was designed to transfer the raw data to commercial PCs. We can now use this system to obtain the individual antenna data streams and subsequently correlate them in software, bypassing the hardware correlator entirely. Software processing permits synthesis of narrower frequency bins, plus easier access for iterations to improve the near field model or correct a poor ephemeris a posteriori. This system could also be used to achieve high time resolution on strong sources. We have recently used this system to observe near Earth asteroid (25143) Itokawa, a sub-kilometer sized object that passed within 0.013 AU of the Earth and is the target of the Japanese Hayabusa mission. The National Radio Astronomy Observatory is a facility of the NSF operated under cooperative agreement by

  16. Estimation of uncertainty bounds for individual particle image velocimetry measurements from cross-correlation peak ratio

    Science.gov (United States)

    Charonko, John J.; Vlachos, Pavlos P.

    2013-06-01

    Numerous studies have established firmly that particle image velocimetry (PIV) is a robust method for non-invasive, quantitative measurements of fluid velocity, and that when carefully conducted, typical measurements can accurately detect displacements in digital images with a resolution well below a single pixel (in some cases well below a hundredth of a pixel). However, to date, these estimates have only been able to provide guidance on the expected error for an average measurement under specific image quality and flow conditions. This paper demonstrates a new method for estimating the uncertainty bounds to within a given confidence interval for a specific, individual measurement. Here, cross-correlation peak ratio, the ratio of primary to secondary peak height, is shown to correlate strongly with the range of observed error values for a given measurement, regardless of flow condition or image quality. This relationship is significantly stronger for phase-only generalized cross-correlation PIV processing, while the standard correlation approach showed weaker performance. Using an analytical model of the relationship derived from synthetic data sets, the uncertainty bounds at a 95% confidence interval are then computed for several artificial and experimental flow fields, and the resulting errors are shown to match closely to the predicted uncertainties. While this method stops short of being able to predict the true error for a given measurement, knowledge of the uncertainty level for a PIV experiment should provide great benefits when applying the results of PIV analysis to engineering design studies and computational fluid dynamics validation efforts. Moreover, this approach is exceptionally simple to implement and requires negligible additional computational cost.

  17. Technical Note: Detection of gas bubble leakage via correlation of water column multibeam images

    Directory of Open Access Journals (Sweden)

    J. Schneider von Deimling

    2012-03-01

    Full Text Available Hydroacoustic detection of natural gas release from the seafloor has been conducted in the past by using singlebeam echosounders. In contrast, modern multibeam swath mapping systems allow much wider coverage, higher resolution, and offer 3-D spatial correlation. Up to the present, the extremely high data rate hampers water column backscatter investigations and more sophisticated visualization and processing techniques are needed. Here, we present water column backscatter data acquired with a 50 kHz prototype multibeam system over a period of 75 seconds. Display types are of swath-images as well as of a "re-sorted" singlebeam presentation. Thus, individual and/or groups of gas bubbles rising from the 24 m deep seafloor clearly emerge in the acoustic images, making it possible to estimate rise velocities. A sophisticated processing scheme is introduced to identify those rising gas bubbles in the hydroacoustic data. We apply a cross-correlation technique adapted from particle imaging velocimetry (PIV to the acoustic backscatter images. Temporal and spatial drift patterns of the bubbles are assessed and are shown to match very well to measured and theoretical rise patterns. The application of this processing to our field data gives clear results with respect to unambiguous bubble detection and remote bubble rise velocimetry. The method can identify and exclude the main source of misinterpretations, i.e. fish-mediated echoes. Although image-based cross-correlation techniques are well known in the field of fluid mechanics for high resolution and non-inversive current flow field analysis, we present the first application of this technique as an acoustic bubble detector.

  18. Intra-field CDU map correlation between SEMs and aerial image characterization

    Science.gov (United States)

    Ning, Guoxiang; Philipp, Peter; Litt, Lloyd C.; Meusemann, Stefan; Thaler, Thomas; Schulz, Kristian; Tschinkl, Martin; Ackmann, Paul

    2014-09-01

    Reticle critical dimension uniformity (CDU) is one of the major sources of wafer CD variations which include both inter-field variations and intra-field variations. Generally, wafer critical dimension (CD) measurement sample size interfield is much less than intra-field. Intra-field CDU correction requires time-consumption of metrology. In order to improve wafer intra-field CDU, several methods can be applied such as intra-field dose correction to improve wafer intra-field CDU. Corrections can be based on CD(SEM) or aerial image metrology data from the reticle. Reticle CDU and wafer CDU maps are based on scanning electron microscope (SEM) metrology, while reticle inspection intensity mapping (NuFLare 6000) and wafer level critical dimension (WLCD) utilize aerial images or optical techniques. Reticle inspecton tools such as those from KLA and NuFlare, offer the ability to collect optical measurement data to produce an optical CDU map. WLCD of Zeiss has the advantage of using the same illumination condition as the scanner to measure the aerial images or optical CD. In this study, the intra-field wafer CDU map correlation between SEMs and aerial images are characterized. The layout of metrology structures is very important for the correlation between wafer intra-field CDU, measured by SEM, and the CDU determined by aerial images. The selection of metrology structures effects on the correlation to SEM CD to wafer is also demonstrated. Both reticle CDU, intensity CDU and WLCD are candidates for intra-field wafer CDU characterization and the advantages and limitations of each approach are discussed.

  19. Fast method of constructing image correlations to build a free network based on image multivocabulary trees

    Science.gov (United States)

    Zhan, Zongqian; Wang, Xin; Wei, Minglu

    2015-05-01

    In image-based three-dimensional (3-D) reconstruction, one topic of growing importance is how to quickly obtain a 3-D model from a large number of images. The retrieval of the correct and relevant images for the model poses a considerable technological challenge. The "image vocabulary tree" has been proposed as a method to search for similar images. However, a significant drawback of this approach is identified in its low time efficiency and barely satisfactory classification result. The method proposed is inspired by, and improves upon, some recent methods. Specifically, vocabulary quality is considered and multivocabulary trees are designed to improve the classification result. A marked improvement was, indeed, observed in our evaluation of the proposed method. To improve time efficiency, graphics processing unit (GPU) computer unified device architecture parallel computation is applied in the multivocabulary trees. The results of the experiments showed that the GPU was three to four times more efficient than the enumeration matching and CPU methods when the number of images is large. This paper presents a reliable reference method for the rapid construction of a free network to be used for the computing of 3-D information.

  20. Correlation imaging method based on local wavenumber for interpreting magnetic data

    Science.gov (United States)

    Ma, Guoqing; Liu, Cai; Xu, Jiashu; Meng, Qingfa

    2017-03-01

    Depth estimation is a general task in the interpretation of magnetic data, and local wavenumber is an effective tool to accomplish this task, but this method requires the structural index of causative source when applies it to compute the depth of the source, which is hard to obtain for an unknown area. In this paper, we suggested a correlation imaging method to interpret magnetic data, which uses the correlation coefficient of local wavenumber of real magnetic data and transformative local wavenumber of synthetic magnetic data generated by assumed source to estimate the location of the source, and this method does not require any priori information of the source and does not require solving any matrix. The computation steps as follows, first, we assume that the causative sources are distributed regularly as a rectangular grid, and then separately compute the correlation coefficient of the local wavenumber of real data and local wavenumber of the anomaly generated by each assumed source, and the correlation coefficient gets maximum when the location parameters of the assumed source are in accord with the true locations of real sources. The synthetic tested results show that this method can obtain the location of magnetic source effectively and correctly, and is insensitive to magnetization direction and noise. This method is also applied to measured magnetic data, and get the location parameters of the source.

  1. Damage Assessment of Composite Structures Using Digital Image Correlation

    Science.gov (United States)

    Caminero, M. A.; Lopez-Pedrosa, M.; Pinna, C.; Soutis, C.

    2014-02-01

    The steady increase of Carbon-Fiber Reinforced Polymer (CFRP) Structures in modern aircraft will reach a new dimension with the entry into service of the Boeing 787 and Airbus 350. Replacement of damaged parts will not be a preferable solution due to the high level of integration and the large size of the components involved. Consequently the need to develop repair techniques and processes for composite components is readily apparent. Bonded patch repair technologies provide an alternative to mechanically fastened repairs with significantly higher performance, especially for relatively thin skins. Carefully designed adhesively bonded patches can lead to cost effective and highly efficient repairs in comparison with conventional riveted patch repairs that cut fibers and introduce highly strained regions. In this work, the assessment of the damage process taking place in notched (open-hole) specimens under uniaxial tensile loading was studied. Two-dimensional (2D) and three-dimensional (3D) Digital Image Correlation (DIC) techniques were employed to obtain full-field surface strain measurements in carbon-fiber/epoxy T700/M21 composite plates with different stacking sequences in the presence of an open circular hole. Penetrant enhanced X-ray radiographs were taken to identify damage location and extent after loading around the hole. DIC strain fields were compared to finite element predictions. In addition, DIC techniques were used to characterise damage and performance of adhesively bonded patch repairs in composite panels under tensile loading. This part of work relates to strength/stiffness restoration of damaged composite aircraft that becomes more important as composites are used more extensively in the construction of modern jet airliners. The behaviour of bonded patches under loading was monitored using DIC full-field strain measurements. Location and extent of damage identified by X-ray radiography correlates well with DIC strain results giving confidence to

  2. Magnetic resonance imaging and histology correlation in Cushing's disease.

    Science.gov (United States)

    Masopust, Václav; Netuka, David; Beneš, Vladimír; Májovský, Martin; Belšán, Tomáš; Bradáč, Ondřej; Hořínek, Daniel; Kosák, Mikuláš; Hána, Václav; Kršek, Michal

    We continuously look for new techniques to improve the radicality of resection and to eliminate the negative effects of surgery. One of the methods that has been implemented in the perioperative management of Cushing's disease was the combination of three magnetic resonance imaging (MRI) sequences: SE, SPGR and fSPGR. We enrolled 41 patients (11 males, 30 females) diagnosed with Cushing's disease. A 3D tumour model with a navigation console was developed using each SPGR, fSPGR and SE sequence. The largest model was then used. In all cases, a standard four-handed, bi-nostril endoscopic endonasal technique was used. Endocrinological follow-up evaluation using morning cortisol sampling was performed for 6-34 months in our study. In total, 36 patients (88%) were disease-free following surgery. Our results indicate we achieved 100% sensitivity of MR. Overall, the conformity of at least one donor site, as compared with the places designated on MR, was in 78% of patients. We searched the place of compliance in individual locations. There is a consensus in individual locations in 63 of the 123 cases (or 56%). The correlation gamma function at a 5% significance level was then 0.27. The combination of MR sequences (SE, SPGR, fSPGR), neuronavigation system and iMRI led to increased sensitivity of up to 100%. Specificity reached 56% in our study. We found a high success rate in surgical procedure in terms of the correlation between MR findings and histology, which leads to remission of Cushing's disease. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

  3. Distortion-Invariant Binary Image Recognition Based on Central Projection Correlation

    Institute of Scientific and Technical Information of China (English)

    WU Yaming; XIAO Yanping; SUN Fanghong; FANG Nian

    2001-01-01

    A method of central projection correlation which is invariant to distortion of shift, scale and rotation of the binary target image is proposed. A 2-D binary image is transformed into an 1-D central projection referring to the centroid of the binary image. The distortion-invariant central projection correlation is successfully performed by computer simulations and its optical implementation is presented.

  4. Traffic Sign Recognition System based on Cambridge Correlator Image Comparator

    OpenAIRE

    J. Turan; L. Ovsenik; T. Harasthy

    2012-01-01

    Paper presents basic information about application of Optical Correlator (OC), specifically Cambridge Correlator, in system to recognize of traffic sign. Traffic Sign Recognition System consists of three main blocks, Preprocessing, Optical Correlator and Traffic Sign Identification. The Region of Interest (ROI) is defined and chosen in preprocessing block and then goes to Optical Correlator, where is compared with database of Traffic Sign. Output of Optical Correlation is correlation plane, w...

  5. IMPROVED SYNTHETIC APERTURE SONAR MOTION COMPENSATION COMBINED DPCA WITH SUB-APERTURE IMAGE CORRELATION

    Institute of Scientific and Technical Information of China (English)

    Liu Wei; Zhang Chunhua; Liu Jiyuan

    2009-01-01

    Estimation precision of Displaced Phase Center Algorithm (DPCA) is affected by the number of displaced phase center pairs, the bandwidth of transmitting signal and many other factors. Detailed analysis is made on DPCA's estimation precision. Analysis results show that the directional vector estimation precision of DPCA is low, which will produce accumulating errors when phase centers' track is estimated. Because of this reason, DPCA suffers from accumulating errors seriously. To overcome this problem, a method combining DPCA with Sub Aperture Image Correlation (SAIC) is presented. Large synthetic aperture is divided into sub-apertures. Micro errors in sub-aperture are estimated by DPCA and compensated to raw echo data. Bulk errors between sub-apertures are estimated by SAIC and compensated directly to sub-aperture images. After that, sub-aperture images are directly used to generate ultimate SAS image. The method is applied to the lake-trial dataset of a 20 kHz SAS prototype system. Results show the method can successfully remove the accumulating error and produce a better SAS image.

  6. Parametric image alignment using enhanced correlation coefficient maximization.

    Science.gov (United States)

    Evangelidis, Georgios D; Psarakis, Emmanouil Z

    2008-10-01

    In this work we propose the use of a modified version of the correlation coefficient as a performance criterion for the image alignment problem. The proposed modification has the desirable characteristic of being invariant with respect to photometric distortions. Since the resulting similarity measure is a nonlinear function of the warp parameters, we develop two iterative schemes for its maximization, one based on the forward additive approach and the second on the inverse compositional method. As it is customary in iterative optimization, in each iteration, the nonlinear objective function is approximated by an alternative expression for which the corresponding optimization is simple. In our case we propose an efficient approximation that leads to a closed-form solution (per iteration) which is of low computational complexity, the latter property being particularly strong in our inverse version. The proposed schemes are tested against the Forward Additive Lucas-Kanade and the Simultaneous Inverse Compositional (SIC) algorithm through simulations. Under noisy conditions and photometric distortions, our forward version achieves more accurate alignments and exhibits faster convergence whereas our inverse version has similar performance as the SIC algorithm but at a lower computational complexity.

  7. GRAY TONE FILTERING ON ERS-SAR IMAGES APPLIED TO CHANGE DETECTION AND MAPPING

    Directory of Open Access Journals (Sweden)

    Gilles André

    2011-05-01

    Full Text Available In SAR images, the pixel values are tightly related to physical parameters of the soil such as topography, roughness and humidity, regardless to atmospheric conditions. Therefore, SAR images may be used to detect, and quantify changes in land cover, by comparison of time series SAR data. Classical change detection techniques from SAR images are based on additive synthesis of RGB colors and arithmetic operations between images. The noisy aspect of ERS image due to the original speckle is an obstacle for available mapping and quantification of the changes. Here, statistical and morphological filters are used to reduce the speckle noise. Combined techniques of change detection and noise filtering are applied here to assess and map from ERS-SAR images the impact of regular or catastrophic flood and deforestation in the East Coast of Madagascar.

  8. A simplification of the fractional Hartley transform applied to image security system in phase

    Science.gov (United States)

    Jimenez, Carlos J.; Vilardy, Juan M.; Perez, Ronal

    2017-01-01

    In this work we develop a new encryption system for encoded image in phase using the fractional Hartley transform (FrHT), truncation operations and random phase masks (RPMs). We introduce a simplification of the FrHT with the purpose of computing this transform in an efficient and fast way. The security of the encryption system is increased by using nonlinear operations, such as the phase encoding and the truncation operations. The image to encrypt (original image) is encoded in phase and the truncation operations applied in the encryption-decryption system are the amplitude and phase truncations. The encrypted image is protected by six keys, which are the two fractional orders of the FrHTs, the two RPMs and the two pseudorandom code images generated by the amplitude and phase truncation operations. All these keys have to be correct for a proper recovery of the original image in the decryption system. We present digital results that confirm our approach.

  9. Approach of Image Stream Apply to X-ray Scan Imaging Equipment

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Wei

    2013-01-01

    A thin beam of X-rays is scanned over the surface of the mass being examined as the material moved on the belt.Jumped spots arranged make up a scan line,and lines constituting the surface.The scan lines of data obtained sequentially,which is re-arranged form an image pixel data in the memory,constituting a digital image displayed on a display.

  10. Image Enhancer: A Graphic Editor to Apply Numerous Effects in Digital Image

    Directory of Open Access Journals (Sweden)

    Abhisek Hazra

    2014-12-01

    Full Text Available Image Enhancer is an open source, portable graphic editor developed for Windows platform. It is equipped with an enriched set of digital imaging filters with advanced computer vision techniques embedded within, like Interest Point Detection (Susan Corner Detector, Linear Edge Detection (Simple, Sobel, Canny, Histogram Equalization, Dithering (Bayer, Burkes, Sierra, Jarvis Judis Ninke, Transforming to Polar images and vice versa etc.  Image Enhancer was released under GNU Lesser General Public License (LGPL and the software was made available from the Microsoft’s open source project hosting repository Codeplex (http://imageenhancer.codeplex.com. Image Enhancer was tested and hosted by several popular software archives like SoftPedia, CNET, Freeware Files, ZDNet, Soft Tango and others. A stable Release Candidate (RC version has been made available in which some major modifications were done which were not present in the earlier Beta version. The download link for the Image Enhancer (both Release Candidate & Beta Version from CodePlex repository is (http://imageenhancer.codeplex.com/releases.

  11. Infrared thermography coupled with digital image correlation in studying plastic deformation on the mesoscale level

    Science.gov (United States)

    Wang, Xiaogang; Witz, Jean-François; El Bartali, Ahmed; Jiang, Chao

    2016-11-01

    This paper focuses on a study of plastic deformation on the mesoscale level by infrared thermography coupled with digital image correlation. First, a novel technique for fully-coupled thermal and kinematic measurements was developed, and the common problem of spatial coupling in the multifield measurement was solved successfully using an image registration method. Then the developed technique was applied to investigate the plastic deformation of a pure aluminium oligocrystal specimen in a tensile test. The deformed specimen manifested high strains of type out-of-plane, which were found closely associated with the crystallographic structure. From a metrological point of view, the out-of-plane effect on the thermographic measurement was analyzed, and the pertinent radiometric artifacts were estimated. The source of errors was verified through a correlation analysis between the estimated artifacts and specimen surface profile. Moreover, the out-of-plane effect on the kinematic measurement was investigated, and the relevant errors were analyzed via the correlation residual. The analysis highlighted the role of the microstructure that played in the plastic deformation and showed that grain boundary was crucial in shaping the heterogeneous deformation patterns for aluminium oligocrystals.

  12. Real-time three-dimensional digital image correlation for biomedical applications

    Science.gov (United States)

    Wu, Rong; Wu, Hua; Arola, Dwayne; Zhang, Dongsheng

    2016-10-01

    Digital image correlation (DIC) has been successfully applied for evaluating the mechanical behavior of biological tissues. A three-dimensional (3-D) DIC system has been developed and applied to examining the motion of bones in the human foot. To achieve accurate, real-time displacement measurements, an algorithm including matching between sequential images and image pairs has been developed. The system was used to monitor the movement of markers which were attached to a precisely motorized stage. The accuracy of the proposed technique for in-plane and out-of-plane measurements was found to be -0.25% and 1.17%, respectively. Two biomedical applications were presented. In the experiment involving the foot arch, a human cadaver lower leg and foot specimen were subjected to vertical compressive loads up to 700 N at a rate of 10 N/s and the 3-D motions of bones in the foot were monitored in real time. In the experiment involving distal tibio fibular syndesmosis, a human cadaver lower leg and foot specimen were subjected to a monotonic rotational torque up to 5 Nm at a speed of 5 deg per min and the relative displacements of the tibia and fibula were monitored in real time. Results showed that the system could reach a frequency of up to 16 Hz with 6 points measured simultaneously. This technique sheds new lights on measuring 3-D motion of bones in biomechanical studies.

  13. Image Correlation Pattern Optimization for Micro-Scale In-Situ Strain Measurements

    Science.gov (United States)

    Bomarito, G. F.; Hochhalter, J. D.; Cannon, A. H.

    2016-01-01

    The accuracy and precision of digital image correlation (DIC) is a function of three primary ingredients: image acquisition, image analysis, and the subject of the image. Development of the first two (i.e. image acquisition techniques and image correlation algorithms) has led to widespread use of DIC; however, fewer developments have been focused on the third ingredient. Typically, subjects of DIC images are mechanical specimens with either a natural surface pattern or a pattern applied to the surface. Research in the area of DIC patterns has primarily been aimed at identifying which surface patterns are best suited for DIC, by comparing patterns to each other. Because the easiest and most widespread methods of applying patterns have a high degree of randomness associated with them (e.g., airbrush, spray paint, particle decoration, etc.), less effort has been spent on exact construction of ideal patterns. With the development of patterning techniques such as microstamping and lithography, patterns can be applied to a specimen pixel by pixel from a patterned image. In these cases, especially because the patterns are reused many times, an optimal pattern is sought such that error introduced into DIC from the pattern is minimized. DIC consists of tracking the motion of an array of nodes from a reference image to a deformed image. Every pixel in the images has an associated intensity (grayscale) value, with discretization depending on the bit depth of the image. Because individual pixel matching by intensity value yields a non-unique scale-dependent problem, subsets around each node are used for identification. A correlation criteria is used to find the best match of a particular subset of a reference image within a deformed image. The reader is referred to references for enumerations of typical correlation criteria. As illustrated by Schreier and Sutton and Lu and Cary systematic errors can be introduced by representing the underlying deformation with under

  14. MR Imaging of Rotator Cuff Tears: Correlation with Arthroscopy

    Science.gov (United States)

    Bhandary, Sudarshan; Khandige, Ganesh; Kabra, Utkarsh

    2017-01-01

    Introduction Rotator cuff tears are quite common and can cause significant disability. Magnetic Resonance Imaging (MRI) has now emerged as the modality of choice in the preoperative evaluation of patients with rotator cuff injuries, in view of its improved inherent soft tissue contrast and resolution. Aim To evaluate the diagnostic accuracy of routine MRI in the detection and characterisation of rotator cuff tears, by correlating the findings with arthroscopy. Materials and Methods This prospective study was carried out between July 2014 and August 2016 at the AJ Institute of Medical Sciences, Mangalore, Karnataka, India. A total of 82 patients were diagnosed with rotator cuff injury on MRI during this period, out of which 45 patients who underwent further evaluation with arthroscopy were included in this study. The data collected was analysed for significant correlation between MRI diagnosis and arthroscopic findings using kappa statistics. The sensitivity, specificity, predictive value and accuracy of MRI for the diagnosis of full and partial thickness tears were calculated using arthroscopic findings as the reference standard. Results There were 27 males and 18 females in this study. The youngest patient was 22 years and the oldest was 74 years. Majority of rotator cuff tears (78%) were seen in patients above the age of 40 years. MRI showed a sensitivity of 89.6%, specificity of 100%, positive predictive value of 100% and negative predictive value of 83.3% for the diagnosis of full thickness rotator cuff tears. For partial thickness tears, MRI showed a sensitivity of 100%, specificity of 86.6%, positive predictive value of 78.9% and negative predictive value of 100%. The accuracy was 93.1% for full thickness tears and 91.1% for partial thickness tears. The p-value was less than 0.01 for both full and partial thickness tears. There was good agreement between the MRI and arthroscopic findings, with kappa value of 0.85 for full thickness tears and 0.81 for partial

  15. GEOMETRICAL CORRELATION AND MATCHING OF 2D IMAGE SHAPES

    OpenAIRE

    Y. V. Vizilter; S. Y. Zheltov

    2012-01-01

    The problem of image correspondence measure selection for image comparison and matching is addressed. Many practical applications require image matching "just by shape" with no dependence on the concrete intensity or color values. Most popular technique for image shape comparison utilizes the mutual information measure based on probabilistic reasoning and information theory background. Another approach was proposed by Pytiev (so called "Pytiev morphology") based on geometrical and algebraic r...

  16. Investigation of spatial correlation in MR images of human cerebral white matter using geostatistical methods

    Energy Technology Data Exchange (ETDEWEB)

    Keil, Fabian

    2014-03-20

    Investigating the structure of human cerebral white matter is gaining interest in the neurological as well as in the neuroscientific community. It has been demonstrated in many studies that white matter is a very dynamic structure, rather than a static construct which does not change for a lifetime. That means, structural changes within white matter can be observed even on short timescales, e.g. in the course of normal ageing, neurodegenerative diseases or even during learning processes. To investigate these changes, one method of choice is the texture analysis of images obtained from white matter. In this regard, MRI plays a distinguished role as it provides a completely non-invasive way of acquiring in vivo images of human white matter. This thesis adapted a statistical texture analysis method, known as variography, to quantify the spatial correlation of human cerebral white matter based on MR images. This method, originally introduced in geoscience, relies on the idea of spatial correlation in geological phenomena: in naturally grown structures near things are correlated stronger to each other than distant things. This work reveals that the geological principle of spatial correlation can be applied to MR images of human cerebral white matter and proves that variography is an adequate method to quantify alterations therein. Since the process of MRI data acquisition is completely different to the measuring process used to quantify geological phenomena, the variographic analysis had to be adapted carefully to MR methods in order to provide a correctly working methodology. Therefore, theoretical considerations were evaluated with numerical samples in a first, and validated with real measurements in a second step. It was shown that MR variography facilitates to reduce the information stored in the texture of a white matter image to a few highly significant parameters, thereby quantifying heterogeneity and spatial correlation distance with an accuracy better than 5

  17. Digital imaging and remote sensing image generator (DIRSIG) as applied to NVESD sensor performance modeling

    Science.gov (United States)

    Kolb, Kimberly E.; Choi, Hee-sue S.; Kaur, Balvinder; Olson, Jeffrey T.; Hill, Clayton F.; Hutchinson, James A.

    2016-05-01

    The US Army's Communications Electronics Research, Development and Engineering Center (CERDEC) Night Vision and Electronic Sensors Directorate (referred to as NVESD) is developing a virtual detection, recognition, and identification (DRI) testing methodology using simulated imagery as a means of augmenting the field testing component of sensor performance evaluation, which is expensive, resource intensive, time consuming, and limited to the available target(s) and existing atmospheric visibility and environmental conditions at the time of testing. Existing simulation capabilities such as the Digital Imaging Remote Sensing Image Generator (DIRSIG) and NVESD's Integrated Performance Model Image Generator (NVIPM-IG) can be combined with existing detection algorithms to reduce cost/time, minimize testing risk, and allow virtual/simulated testing using full spectral and thermal object signatures, as well as those collected in the field. NVESD has developed an end-to-end capability to demonstrate the feasibility of this approach. Simple detection algorithms have been used on the degraded images generated by NVIPM-IG to determine the relative performance of the algorithms on both DIRSIG-simulated and collected images. Evaluating the degree to which the algorithm performance agrees between simulated versus field collected imagery is the first step in validating the simulated imagery procedure.

  18. Performance of third-order ghost imaging with second-order intensity correlation

    Institute of Scientific and Technical Information of China (English)

    Bin Cao; Chunxi Zhang; Pan Ou

    2011-01-01

    @@ The third-order ghost imaging with the second-order intensity correlation is theoretically and experimentally demonstrated.The resolution and visibility of the reconstructed image are discussed,and the relationship between resolution and visibility is analyzed.The theoretical results show that a tradeoff exists between the visibility and resolution of the reconstructed image; the better the image resolution,the worse the image visibility.%The third-order ghost imaging with the second-order intensity correlation is theoretically and experimentally demonstrated. The resolution and visibility of the reconstructed image are discussed, and the relationship between resolution and visibility is analyzed. The theoretical results show that a tradeoff exists between the visibility and resolution of the reconstructed image; the better the image resolution, the worse the image visibility. Numerical simulations are carried out to verify this theory, and a ghost imaging experiment is conducted to validate our calculations. The experimental results agree with the theoretical predictions.

  19. Correlation evaluation of intensity and color band images

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J.M.

    1996-02-01

    The purpose of this project is to determine which of the three color bands--red, green, or blue--to use in providing the best possible correlation and to determine the accuracy with which these color bands correlate in comparison with the correlation of the three color bands with the intensity model. To fulfill this purpose, the correlation technique of template matching is implemented using a correlator. Correlations are implemented with each of the individual color bands and also with the corresponding intensity model. The correlation coefficient resulting from a successful correlation ranges from 0.9 to 1. A coefficient of 1 demonstrates that the feature information varies identically. When analyzing the data collected from the correlations, the following results are obtained. The color band recommended for the most accurate correlation is the green color band. The correlation of the color bands with the intensity model was not as successful in determining the better color band because the correlation coefficients were very low in comparison to the correlation of the individual color bands.

  20. Imaging techniques applied to the study of fluids in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tomutsa, L.; Doughty, D.; Brinkmeyer, A.; Mahmood, S.

    1992-06-01

    Improved imaging techniques were used to study the dynamics of fluid flow and trapping at various scales in porous media. Two-phase and three-phase floods were performed and monitored by computed tomography (CT) scanning and/or nuclear magnetic resonance imaging (NMRI) microscopy. Permeability-porosity correlations obtained from image analysis were combined with porosity distributions from CT scanning to generate spatial permeability distributions within the core which were used in simulations of two-phase floods. Simulation-derived saturation distributions of two-phase processes showed very good agreement with the CT measured values.

  1. Steganography: Applying and Evaluating Two Algorithms for Embedding Audio Data in an Image

    OpenAIRE

    Khaled Nasser ElSayed

    2015-01-01

    Information transmission is increasing with grow of using WEB. So, information security has become very important. Security of data and information is the major task for scientists and political and military people. One of the most secure methods is embedding data (steganography) in different media like text, audio, digital images. this paper present two experiments in steganography of digital audio data file. It applies empirically, two algorithms in steganography in images through random in...

  2. Two-dimensional optical correlation spectroscopy applied to liquid/glass dynamics

    NARCIS (Netherlands)

    Lazonder, Kees; Pshenichnikov, Maxim S.; Wiersma, Douwe A.; Corkum, Paul; Jonas, David M.; Miller, R.J. Dwayne.; Weiner, Andrew M.

    2007-01-01

    Correlation spectroscopy was used to study the effects of temperature and phase changes on liquid and glass solvent dynamics. By assessing the eccentricity of the elliptic shape of a 2D optical correlation spectrum the value of the underlying frequency-frequency correlation function can be retrieved

  3. Modelling laser speckle photographs of decayed teeth by applying a digital image information technique

    Science.gov (United States)

    Ansari, M. Z.; da Silva, L. C.; da Silva, J. V. P.; Deana, A. M.

    2016-09-01

    We report on the application of a digital image model to assess early carious lesions on teeth. When decay is in its early stages, the lesions were illuminated with a laser and the laser speckle images were obtained. Due to the differences in the optical properties between healthy and carious tissue, both regions produced different scatter patterns. The digital image information technique allowed us to produce colour-coded 3D surface plots of the intensity information in the speckle images, where the height (on the z-axis) and the colour in the rendering correlate with the intensity of a pixel in the image. The quantitative changes in colour component density enhance the contrast between the decayed and sound tissue, and visualization of the carious lesions become significantly evident. Therefore, the proposed technique may be adopted in the early diagnosis of carious lesions.

  4. Snapping Sharks, Maddening Mindreaders, and Interactive Images: Teaching Correlation.

    Science.gov (United States)

    Mitchell, Mark L.

    Understanding correlation coefficients is difficult for students. A free computer program that helps introductory psychology students distinguish between positive and negative correlation, and which also teaches them to understand the differences between correlation coefficients of different size is described in this paper. The program is…

  5. Steganography: Applying and Evaluating Two Algorithms for Embedding Audio Data in an Image

    Directory of Open Access Journals (Sweden)

    Khaled Nasser ElSayed

    2015-03-01

    Full Text Available Information transmission is increasing with grow of using WEB. So, information security has become very important. Security of data and information is the major task for scientists and political and military people. One of the most secure methods is embedding data (steganography in different media like text, audio, digital images. this paper present two experiments in steganography of digital audio data file. It applies empirically, two algorithms in steganography in images through random insertion of digital audio data using bytes and pixels in image files. Finally, it evaluates both experiments, in order to enhance security of transmitted data.

  6. ENTROPY BASED DATA HIDING ON DOCUMENT IMAGES APPLIED ON DRDM APPROACH

    Directory of Open Access Journals (Sweden)

    Sadia Aslam

    2013-03-01

    Full Text Available This paper presents a data hiding application for document images providing security. Document images should be in bitmap format as well as grayscale in nature otherwise the developed system will automatically change it to grayscale. The system accepts any grayscale document image as an input and applies the developed technique on it. Developed technique is based on Entropy Based that selects the suitable areas in an image for that data insertion purpose. Output produced by the system is the processed document that is data embedded. Processed document should not look different from the original image means its visual quality should be high. The system is successfully tested for the test cases generated to check the effectiveness, quality and validation of the system. The system is developed using Matlab 7.7.0 (R2008b for the development of front end as well as the back end.

  7. Large range rotation distortion measurement for remote sensing images based on volume holographic optical correlator

    Science.gov (United States)

    Zheng, Tianxiang; Cao, Liangcai; Zhao, Tian; He, Qingsheng; Jin, Guofan

    2012-10-01

    Volume holographic optical correlator can compute the correlation results between images at a super-high speed. In the application of remote imaging processing such as scene matching, 6,000 template images have been angularly multiplexed in the photorefractive crystal and the 6,000 parallel processing channels are achieved. In order to detect the correlation pattern of images precisely and distinguishingly, an on-off pixel inverted technology of images is proposed. It can fully use the CCD's linear range for detection and expand the normalized correlation value differences as the target image rotates. Due to the natural characteristics of the remote sensing images, the statistical formulas between the rotation distortions and the correlation results can be estimated. The rotation distortion components can be estimated by curve fitting method with the data of correlation results. The intensities of the correlation spots are related to the distortion between the two images. The rotation distortion could be derived from the intensities in the post processing procedure. With 18 rotations of the input image and sending them into the volume holographic system, the detection of the rotation variation in the range of 180° can be fulfilled. So the large range rotation distortion detection is firstly realized. It offers a fast, large range rotation measurement method for image distortions.

  8. Optical Flow Applied to Time-Lapse Image Series to Estimate Glacier Motion in the Southern Patagonia Ice Field

    Science.gov (United States)

    Lannutti, E.; Lenzano, M. G.; Toth, C.; Lenzano, L.; Rivera, A.

    2016-06-01

    In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis.

  9. Correlative cathodoluminescence and near-infrared fluorescence imaging for bridging from nanometer to millimeter scale bioimaging.

    Science.gov (United States)

    Niioka, H; Fukushima, S; Ichimiya, M; Ashida, M; Miyake, J; Araki, T; Hashimoto, M

    2014-11-01

    Correlative light and electron microscopy (CLEM) is one attractive method of observing biological specimens because it combines the advantages of both light microscopy (LM) and electron microscopy (EM). In LM, specimens are fully hydrated, and molecular species are distinguished based on the fluorescence colors of probes. EM provides both high-spatial-resolution images superior to those obtained with LM and ultrastructural information of cellular components. The combination of LM and EM gives much more information than either method alone, which helps us to analyze cellular function in more detail.We propose a Y2O3:Tm,Yb phosphor nanoparticle which allows upconversion luminescence (UCL) imaging with near-infrared (NIR) light excitation and cathodoluminescence (CL) imaging [1], where the light emission induced by an electron beam is called cathodoluminescence (CL). Due to electron beam excitation, the spatial resolution of CL microscopy is on the order of nanometers [2,3]. Upconversion is a process in which lower energy, longer wavelength excitation light is transduced to higher energy, shorter wavelength emission light. So far, in LM observation for CLEM, ultraviolet (UV) or visible light has been used for excitation. However, UV and visible light have limited ability to observe deep tissue regions due to absorption, scattering, and autofluorescence. On the other hand, NIR light does not suffer from these problems. Rare-earth-doped upconversion nanophosphors have been applied to biological imaging because of the advantages of NIR excitation [4].We investigated the UCL and CL spectra of Y2O3:Tm,Yb nanophosphors. Y2O3:Tm,Yb nanophosphors that emit visible and near-infrared UCL under 980nm irradiation and blue CL via electron beam excitation. To confirm bimodality of our nanophosphors, correlative UCL/CL images of the nanophosphors were obtained for the same region. The nanophosphors were poured onto a P doped Si substrate (Fig. 1(a)) and were irradiated with 980 nm

  10. k-space image correlation to probe the intracellular dynamics of gold nanoparticles

    Science.gov (United States)

    Bouzin, M.; Sironi, L.; Chirico, G.; D'Alfonso, L.; Inverso, D.; Pallavicini, P.; Collini, M.

    2016-04-01

    The collective action of dynein, kinesin and myosin molecular motors is responsible for the intracellular active transport of cargoes, vesicles and organelles along the semi-flexible oriented filaments of the cytoskeleton. The overall mobility of the cargoes upon binding and unbinding to motor proteins can be modeled as an intermittency between Brownian diffusion in the cell cytoplasm and active ballistic excursions along actin filaments or microtubules. Such an intermittent intracellular active transport, exhibited by star-shaped gold nanoparticles (GNSs, Gold Nanostars) upon internalization in HeLa cancer cells, is investigated here by combining live-cell time-lapse confocal reflectance microscopy and the spatio-temporal correlation, in the reciprocal Fourier space, of the acquired image sequences. At first, the analytical theoretical framework for the investigation of a two-state intermittent dynamics is presented for Fourier-space Image Correlation Spectroscopy (kICS). Then simulated kICS correlation functions are employed to evaluate the influence of, and sensitivity to, all the kinetic and dynamic parameters the model involves (the transition rates between the diffusive and the active transport states, the diffusion coefficient and drift velocity of the imaged particles). The optimal procedure for the analysis of the experimental data is outlined and finally exploited to derive whole-cell maps for the parameters underlying the GNSs super-diffusive dynamics. Applied here to the GNSs subcellular trafficking, the proposed kICS analysis can be adopted for the characterization of the intracellular (super-) diffusive dynamics of any fluorescent or scattering biological macromolecule.

  11. A 360-deg Digital Image Correlation system for materials testing

    Science.gov (United States)

    Genovese, K.; Cortese, L.; Rossi, M.; Amodio, D.

    2016-07-01

    The increasing research interest toward natural and advanced engineered materials demands new experimental protocols capable of retrieving highly dense sets of experimental data on the full-surface of samples under multiple loading conditions. Such information, in fact, would allow to capture the possible heterogeneity and anisotropy of the material by using up-to-date inverse characterization methods. Although the development of object-specific test protocols could represent the optimal choice to address this need, it is unquestionable that universal testing machines (UTM) remain the most widespread and versatile option to test materials and components in both academic and industrial contexts. A major limitation of performing standard material tests with UTM, however, consists in the scarce information obtainable with the commonly associated sensors since they provide only global (LVDTs, extensometers, 2D-video analyzers) or local (strain gages) measures of displacement and strain. This paper presents a 3D Digital Image Correlation (DIC) system developed to perform highly accurate full-surface 360-deg measurements on either standard or custom-shaped samples under complex loading within universal testing machines. To this aim, a low cost and easy to setup video rig was specifically designed to overcome the practical limitations entailed with the integration of a multi-camera system within an already existing loading frame. In particular, the proposed system features a single SLR digital camera moved through multiple positions around the specimen by means of a large rotation stage. A proper calibration and data-processing procedure allows to automatically merge the experimental data obtained from the multiple views with an accuracy of 10-2 m m . The results of a full benchmarking of the metrological performances of the system are here reported and discussed together with illustrative examples of full-360-deg shape and deformation measurements on a Grade X65 steel

  12. Pulsed terahertz spectroscopy and imaging applied to inspection of explosives and inflammable liquids

    Science.gov (United States)

    Yamamoto, Kohji; Yamaguchi, Mariko; Miyamaru, Fumiaki; Tani, Masahiko; Hangyo, Masanori; Ikeda, Takeshi; Matsushita, Akira; Koide, Kenji; Tatsuno, Michiaki; Manami, Yukio

    We carried out applied researches on the pulsed terahertz spectroscopy and the terahertz imaging to detect the C-4 explosive hidden in a mail and inflammable liquids stored in plastic bottles. We confirm that THz techniques are quite efficient at contactless and nondestructive inspection of hazardous materials used in terrorist activities.

  13. Joint Applied Optics and Chinese Optics Letters feature introduction: digital holography and three-dimensional imaging.

    Science.gov (United States)

    Poon, Ting-Chung

    2011-12-01

    This feature issue serves as a pilot issue promoting the joint issue of Applied Optics and Chinese Optics Letters. It focuses upon topics of current relevance to the community working in the area of digital holography and 3-D imaging. © 2011 Optical Society of America

  14. Synthetic Aperture Focusing Applied to Imaging Using a Rotating Single Element Transducer

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2007-01-01

    This paper applies the concept of virtual sources and mono-static synthetic aperture focusing (SAF) to 2-dimensional imaging with a single rotating mechanically focused concave element with the objective of improving lateral resolution and signal-to-noise ratio (SNR). The geometrical focal point ...

  15. Joint Applied Optics and Chinese Optics Letters feature introduction: digital holography and three-dimensional imaging

    OpenAIRE

    Poon, Ting-Chung

    2011-01-01

    This feature issue serves as a pilot issue promoting the joint issue of Applied Optics and Chinese Optics Letters. It focuses upon topics of current relevance to the community working in the area of digital holography and 3-D imaging. (C) 2011 Optical Society of America

  16. Applying two-photon excitation fluorescence lifetime imaging microscopy to study photosynthesis in plant leaves

    NARCIS (Netherlands)

    Broess, K.; Borst, J.W.; Amerongen, van H.

    2009-01-01

    This study investigates to which extent two-photon excitation (TPE) fluorescence lifetime imaging microscopy can be applied to study picosecond fluorescence kinetics of individual chloroplasts in leaves. Using femtosecond 860 nm excitation pulses, fluorescence lifetimes can be measured in leaves of

  17. Patient-specific minimum-dose imaging protocols for statistical image reconstruction in C-arm cone-beam CT using correlated noise injection

    Science.gov (United States)

    Wang, A. S.; Stayman, J. W.; Otake, Y.; Khanna, A. J.; Gallia, G. L.; Siewerdsen, J. H.

    2014-03-01

    Purpose: A new method for accurately portraying the impact of low-dose imaging techniques in C-arm cone-beam CT (CBCT) is presented and validated, allowing identification of minimum-dose protocols suitable to a given imaging task on a patient-specific basis in scenarios that require repeat intraoperative scans. Method: To accurately simulate lower-dose techniques and account for object-dependent noise levels (x-ray quantum noise and detector electronics noise) and correlations (detector blur), noise of the proper magnitude and correlation was injected into the projections from an initial CBCT acquired at the beginning of a procedure. The resulting noisy projections were then reconstructed to yield low-dose preview (LDP) images that accurately depict the image quality at any level of reduced dose in both filtered backprojection and statistical image reconstruction. Validation studies were conducted on a mobile C-arm, with the noise injection method applied to images of an anthropomorphic head phantom and cadaveric torso across a range of lower-dose techniques. Results: Comparison of preview and real CBCT images across a full range of techniques demonstrated accurate noise magnitude (within ~5%) and correlation (matching noise-power spectrum, NPS). Other image quality characteristics (e.g., spatial resolution, contrast, and artifacts associated with beam hardening and scatter) were also realistically presented at all levels of dose and across reconstruction methods, including statistical reconstruction. Conclusion: Generating low-dose preview images for a broad range of protocols gives a useful method to select minimum-dose techniques that accounts for complex factors of imaging task, patient-specific anatomy, and observer preference. The ability to accurately simulate the influence of low-dose acquisition in statistical reconstruction provides an especially valuable means of identifying low-dose limits in a manner that does not rely on a model for the nonlinear

  18. Investigation of MINACE composite filter capabilities for multicolor images correlation recognition purposes

    Science.gov (United States)

    Evtikhiev, N. N.; Zlokazov, E. Yu; Petrova, E. K.; Starikov, R. S.; Shaulskiy, D. V.

    2016-08-01

    Article represents the results of investigations in the area of distortion invariant images recognition using composite correlation filters. One of the most successive for application is a filter known as MINACE (minimum noise and average correlation energy). The capabilities of MINACE filter synthesis for multicolor image recognition problem are discussed.

  19. Remote Sensing Image Classification Applied to the First National Geographical Information Census of China

    Science.gov (United States)

    Yu, Xin; Wen, Zongyong; Zhu, Zhaorong; Xia, Qiang; Shun, Lan

    2016-06-01

    Image classification will still be a long way in the future, although it has gone almost half a century. In fact, researchers have gained many fruits in the image classification domain, but there is still a long distance between theory and practice. However, some new methods in the artificial intelligence domain will be absorbed into the image classification domain and draw on the strength of each to offset the weakness of the other, which will open up a new prospect. Usually, networks play the role of a high-level language, as is seen in Artificial Intelligence and statistics, because networks are used to build complex model from simple components. These years, Bayesian Networks, one of probabilistic networks, are a powerful data mining technique for handling uncertainty in complex domains. In this paper, we apply Tree Augmented Naive Bayesian Networks (TAN) to texture classification of High-resolution remote sensing images and put up a new method to construct the network topology structure in terms of training accuracy based on the training samples. Since 2013, China government has started the first national geographical information census project, which mainly interprets geographical information based on high-resolution remote sensing images. Therefore, this paper tries to apply Bayesian network to remote sensing image classification, in order to improve image interpretation in the first national geographical information census project. In the experiment, we choose some remote sensing images in Beijing. Experimental results demonstrate TAN outperform than Naive Bayesian Classifier (NBC) and Maximum Likelihood Classification Method (MLC) in the overall classification accuracy. In addition, the proposed method can reduce the workload of field workers and improve the work efficiency. Although it is time consuming, it will be an attractive and effective method for assisting office operation of image interpretation.

  20. REMOTE SENSING IMAGE CLASSIFICATION APPLIED TO THE FIRST NATIONAL GEOGRAPHICAL INFORMATION CENSUS OF CHINA

    Directory of Open Access Journals (Sweden)

    X. Yu

    2016-06-01

    Full Text Available Image classification will still be a long way in the future, although it has gone almost half a century. In fact, researchers have gained many fruits in the image classification domain, but there is still a long distance between theory and practice. However, some new methods in the artificial intelligence domain will be absorbed into the image classification domain and draw on the strength of each to offset the weakness of the other, which will open up a new prospect. Usually, networks play the role of a high-level language, as is seen in Artificial Intelligence and statistics, because networks are used to build complex model from simple components. These years, Bayesian Networks, one of probabilistic networks, are a powerful data mining technique for handling uncertainty in complex domains. In this paper, we apply Tree Augmented Naive Bayesian Networks (TAN to texture classification of High-resolution remote sensing images and put up a new method to construct the network topology structure in terms of training accuracy based on the training samples. Since 2013, China government has started the first national geographical information census project, which mainly interprets geographical information based on high-resolution remote sensing images. Therefore, this paper tries to apply Bayesian network to remote sensing image classification, in order to improve image interpretation in the first national geographical information census project. In the experiment, we choose some remote sensing images in Beijing. Experimental results demonstrate TAN outperform than Naive Bayesian Classifier (NBC and Maximum Likelihood Classification Method (MLC in the overall classification accuracy. In addition, the proposed method can reduce the workload of field workers and improve the work efficiency. Although it is time consuming, it will be an attractive and effective method for assisting office operation of image interpretation.

  1. Assessment of Atmospheric Correction Methods for Sentinel-2 MSI Images Applied to Amazon Floodplain Lakes

    Directory of Open Access Journals (Sweden)

    Vitor Souza Martins

    2017-03-01

    Full Text Available Satellite data provide the only viable means for extensive monitoring of remote and large freshwater systems, such as the Amazon floodplain lakes. However, an accurate atmospheric correction is required to retrieve water constituents based on surface water reflectance ( R W . In this paper, we assessed three atmospheric correction methods (Second Simulation of a Satellite Signal in the Solar Spectrum (6SV, ACOLITE and Sen2Cor applied to an image acquired by the MultiSpectral Instrument (MSI on-board of the European Space Agency’s Sentinel-2A platform using concurrent in-situ measurements over four Amazon floodplain lakes in Brazil. In addition, we evaluated the correction of forest adjacency effects based on the linear spectral unmixing model, and performed a temporal evaluation of atmospheric constituents from Multi-Angle Implementation of Atmospheric Correction (MAIAC products. The validation of MAIAC aerosol optical depth (AOD indicated satisfactory retrievals over the Amazon region, with a correlation coefficient (R of ~0.7 and 0.85 for Terra and Aqua products, respectively. The seasonal distribution of the cloud cover and AOD revealed a contrast between the first and second half of the year in the study area. Furthermore, simulation of top-of-atmosphere (TOA reflectance showed a critical contribution of atmospheric effects (>50% to all spectral bands, especially the deep blue (92%–96% and blue (84%–92% bands. The atmospheric correction results of the visible bands illustrate the limitation of the methods over dark lakes ( R W < 1%, and better match of the R W shape compared with in-situ measurements over turbid lakes, although the accuracy varied depending on the spectral bands and methods. Particularly above 705 nm, R W was highly affected by Amazon forest adjacency, and the proposed adjacency effect correction minimized the spectral distortions in R W (RMSE < 0.006. Finally, an extensive validation of the methods is required for

  2. Mixtures of conditional Gaussian scale mixtures applied to multiscale image representations.

    Directory of Open Access Journals (Sweden)

    Lucas Theis

    Full Text Available We present a probabilistic model for natural images that is based on mixtures of Gaussian scale mixtures and a simple multiscale representation. We show that it is able to generate images with interesting higher-order correlations when trained on natural images or samples from an occlusion-based model. More importantly, our multiscale model allows for a principled evaluation. While it is easy to generate visually appealing images, we demonstrate that our model also yields the best performance reported to date when evaluated with respect to the cross-entropy rate, a measure tightly linked to the average log-likelihood. The ability to quantitatively evaluate our model differentiates it from other multiscale models, for which evaluation of these kinds of measures is usually intractable.

  3. Quantification of applied dose in irradiated citrus fruits by DNA Comet Assay together with image analysis.

    Science.gov (United States)

    Cetinkaya, Nurcan; Ercin, Demet; Özvatan, Sümer; Erel, Yakup

    2016-02-01

    The experiments were conducted for quantification of applied dose for quarantine control in irradiated citrus fruits. Citrus fruits exposed to doses of 0.1 to 1.5 kGy and analyzed by DNA Comet Assay. Observed comets were evaluated by image analysis. The tail length, tail moment and tail DNA% of comets were used for the interpretation of comets. Irradiated citrus fruits showed the separated tails from the head of the comet by increasing applied doses from 0.1 to 1.5 kGy. The mean tail length and mean tail moment% levels of irradiated citrus fruits at all doses are significantly different (p Comet Assay may be a practical quarantine control method for irradiated citrus fruits since it has been possible to estimate the applied low doses as small as 0.1 kGy when it is combined with image analysis.

  4. Calibration of stereo-digital image correlation for deformation measurement of large engineering components

    Science.gov (United States)

    Shao, Xinxing; Dai, Xiangjun; Chen, Zhenning; Dai, Yuntong; Dong, Shuai; He, Xiaoyuan

    2016-12-01

    The development of stereo-digital image correlation (stereo-DIC) enables the application of vision-based technique that uses digital cameras to the deformation measurement of materials and structures. Compared with traditional contact measurements, the stereo-DIC technique allows for non-contact measurement, has a non-intrusive characteristic, and can obtain full-field deformation information. In this paper, a speckle-based calibration method is developed to calibrate the stereo-DIC system when the system is applied for deformation measurement of large engineering components. By combining speckle analysis with the classical relative orientation algorithm, relative rotation and translation between cameras can be calibrated based on analysis of experimental speckle images. For validation, the strain fields of a four-point bending beam and an axially loaded concrete column were determined by the proposed calibration method and stereovision measurement. As a practical application, the proposed calibration method was applied for strain measurement of a ductile iron cylindrical vessel in the drop test. The measured results verify that the proposed calibration method is effective for deformation measurement of large engineering components.

  5. Tomographic Imaging of Jakarta Area from Cross-correlation of Seismic Ambient Noise

    Science.gov (United States)

    Pranata, B.; Saygin, E.; Cummins, P. R.; Widiyantoro, S.; Nugraha, A. D.; Harjadi, P.; Suhardjono, S.

    2012-12-01

    Seismic imaging of sediment thickness of Jakarta is crucial where Jakarta city is currently being rapidly developed with major installations and high-rise structures being constructed at a fast pace. Therefore, information of surface geology and surface sediment thickness for Jakarta city is urgently required in order to mitigate the effects of earthquake hazards in the future. Because of this need, we deployed 36 broadband and shortperiod stations across Jakarta to record seismic ambient noise. We apply cross-correlation method to the simultaneously recorded data to retrieve interstation Green's functions. We measure group velocity dispersion of the retrieved Green's functions by applying narrowband filters. Dispersion measurements are then inverted with a nonlinear tomographic technique to image the shallow structure of Jakarta and its surrounding regions. Preliminary results from tomographic maps show low velocities dominantly located in central, west and north Jakarta. While the highest rate obtained is between stations in South Jakarta. This conforms with the known geological conditions in which the structure of sedimentary cover in northern Jakarta is thicker than the southern part.

  6. Implementation of a Direct-Imaging and FX Correlator for the BEST-2 Array

    CERN Document Server

    Foster, Griffin; Magro, Alessio; Price, Danny C; Adami, Kristian Zarb

    2014-01-01

    A new digital backend has been developed for the BEST-2 array at Radiotelescopi di Medicina, INAF-IRA, Italy which allows concurrent operation of an FX correlator, and a direct-imaging correlator and beamformer. This backend serves as a platform for testing some of the spatial Fourier transform concepts which have been proposed for use in computing correlations on regularly gridded arrays. While spatial Fourier transform-based beamformers have been implemented previously, this is to our knowledge, the first time a direct-imaging correlator has been deployed on a radio astronomy array. Concurrent observations with the FX and direct-imaging correlator allows for direct comparison between the two architectures. Additionally, we show the potential of the direct-imaging correlator for time-domain astronomy, by passing a subset of beams though a pulsar and transient detection pipeline. These results provide a timely verification for spatial Fourier transform-based instruments that are currently in commissioning. Th...

  7. Myxoid Adrenocortical Adenoma: Magnetic resonance imaging and pathology correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Un [Dept. of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Suk; Lee, Jun Woo; Lee, Nam Kyung; Ha, Hong Koo; Park, Won Young [Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan (Korea, Republic of)

    2014-04-15

    We report a case of a 74-year-old female with myxoid adrenocortical adenoma which showed different magnetic resonance imaging findings compared to those of a typical adrenocortical adenoma. The myxoid change in the adrenocortical adenoma is a rare form of degeneration. It presents a considerable diagnostic challenge to both radiologists and clinicians because it can mimic other adrenal tumor types on imaging. The MRI findings of the presented case included a high signal intensity on T2-weighted images similar to that of fluid and delayed progressive enhancement.

  8. Continuous-wave Terahertz Imaging Applied to Detect Infestations Caused by Insects in Grain

    Directory of Open Access Journals (Sweden)

    Zuojun Tan

    2014-02-01

    Full Text Available Detection infestations caused by insects in grain are important control measures for ensuring storage longevity, seed quality and food safety. The efficiency of the continuous wave terahertz imaging method to detect infestations caused by insects in wheat kernels was determined in this study. A continuous wave terahertz experimental setup was designed for recording of THz images corresponding to different infestations caused by different life stages of insects. The experimental results indicate that the absorbance is generally highest for un-infested wheat kernels and decreased at later growth stages from THz pseudo-color images. Our study intended to demonstrate how the method of continuous wave Terahertz imaging could be applied to detect Infestations Caused by Insects in Grain.

  9. Pleasant/Unpleasant Filtering for Affective Image Retrieval Based on Cross-Correlation of EEG Features

    Directory of Open Access Journals (Sweden)

    Keranmu Xielifuguli

    2014-01-01

    Full Text Available People often make decisions based on sensitivity rather than rationality. In the field of biological information processing, methods are available for analyzing biological information directly based on electroencephalogram: EEG to determine the pleasant/unpleasant reactions of users. In this study, we propose a sensitivity filtering technique for discriminating preferences (pleasant/unpleasant for images using a sensitivity image filtering system based on EEG. Using a set of images retrieved by similarity retrieval, we perform the sensitivity-based pleasant/unpleasant classification of images based on the affective features extracted from images with the maximum entropy method: MEM. In the present study, the affective features comprised cross-correlation features obtained from EEGs produced when an individual observed an image. However, it is difficult to measure the EEG when a subject visualizes an unknown image. Thus, we propose a solution where a linear regression method based on canonical correlation is used to estimate the cross-correlation features from image features. Experiments were conducted to evaluate the validity of sensitivity filtering compared with image similarity retrieval methods based on image features. We found that sensitivity filtering using color correlograms was suitable for the classification of preferred images, while sensitivity filtering using local binary patterns was suitable for the classification of unpleasant images. Moreover, sensitivity filtering using local binary patterns for unpleasant images had a 90% success rate. Thus, we conclude that the proposed method is efficient for filtering unpleasant images.

  10. Analytical shape determination of fiber-like objects with Virtual Image Correlation

    OpenAIRE

    Semin, Benoit; François, Marc Louis Maurice; Auradou, Harold

    2010-01-01

    10 pages; International audience; This paper reports a method allowing for the determination of the shape of deformed fiber-like objects. Compared to existing methods, it provides analytical results including the local slope and curvature which are of first importance, for instance, in beam mechanics. The presented VIC (Virtual Image Correlation) method consists in looking for the best correlation between the image of the fiber-like object and a virtual beam image, using an algorithm close to...

  11. Multispectral image sharpening using wavelet transform techniques and spatial correlation of edges

    Science.gov (United States)

    Lemeshewsky, George P.; Schowengerdt, Robert A.

    2000-01-01

    Several reported image fusion or sharpening techniques are based on the discrete wavelet transform (DWT). The technique described here uses a pixel-based maximum selection rule to combine respective transform coefficients of lower spatial resolution near-infrared (NIR) and higher spatial resolution panchromatic (pan) imagery to produce a sharpened NIR image. Sharpening assumes a radiometric correlation between the spectral band images. However, there can be poor correlation, including edge contrast reversals (e.g., at soil-vegetation boundaries), between the fused images and, consequently, degraded performance. To improve sharpening, a local area-based correlation technique originally reported for edge comparison with image pyramid fusion is modified for application with the DWT process. Further improvements are obtained by using redundant, shift-invariant implementation of the DWT. Example images demonstrate the improvements in NIR image sharpening with higher resolution pan imagery.

  12. Multimodal Imaging and Clinicopathologic Correlation in Primary Uveal Lymphoma

    Directory of Open Access Journals (Sweden)

    Brandon Erickson

    2016-01-01

    Full Text Available Purpose: We report a rare case of primary uveal lymphoma and characterize it using histopathology and multimodal imaging. Patient and Methods: A 41-year-old male presented with a 2-year history of increasingly blurry vision in his right eye and no systemic symptoms. Examination revealed a retinal detachment and mass lesion in the right eye. Radiologic and histologic testing was performed. Results: Multimodal imaging localized the lesion to the choroid, and fine needle aspiration biopsy diagnosed the lesion as a low-grade B-cell lymphoma. The patient was treated with external beam radiation, resulting in regression of the mass and resolution of the retinal detachment. Conclusions: Primary uveal lymphoma is a rare, usually indolent tumor that carries a good prognosis. In this case, we show that primary uveal lymphoma has distinct findings via histopathology and multimodal imaging, and that imaging after radiation treatment documents disease regression.

  13. Correlates of Bio-Psychosocial Factors on Perceived Body Image ...

    African Journals Online (AJOL)

    DrNneka

    According to medical experts, individuals who are overweight (Body Mass ... exercise program improves physical health, enhance body image, raise ..... behavior in children and adolescents: what places youth at risk and how can these.

  14. Application of Digital Image Correlation to Measurement of Packaging Material Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Jian-Wei Zhou

    2013-01-01

    Full Text Available Among various packaging materials, papers and polymer plastics are the most common due to their light weights, low costs, and other advantages. However, their mechanical properties are difficult to measure precisely because of their softness. To overcome the difficulty, a new measure instrument prototype is proposed based on an optical method known as the digital image correlation (DIC. Experiments are designed to apply the DIC to measure mechanical properties of flexible packaging materials, including the stress-strain relationship, the Poisson ratio, the coefficient of heat expansion, the creep deformation, and the top-pressure deformation of corrugated box. In addition, the low frequency vibration of package is simulated, and the vibration frequencies are measured by DIC. Results obtained in the experiments illustrate the advantages of the DIC over traditional methods: noncontact, no reinforced effect, high precision over entire area, wide measurement range, and good measurement stability.

  15. Correlating structure and fluorescence dynamics of quantum dot clusters using super-resolution imaging

    Science.gov (United States)

    Ryan, Duncan P.; Goodwin, Peter M.; Sheehan, Chris J.; Whitcomb, Kevin J.; Gelfand, Martin P.; Van Orden, Alan

    2016-02-01

    Clusters of quantum dots exhibit fluorescent behavior that differs from that of individual particles. Bulk measurements involving a large number of particles obscure these dynamics. Synthesizing clusters with 5-10 particles enables the study of collective behavior where single-molecule fluorescence techniques can be applied. Super-resolution microscopy of these clusters correlated with SEM imaging reveals the influence of geometry and structure on emission dynamics. Signatures of energy transfer can be seen in the form of enhanced blinking. Motion of the emission center of the cluster is tracked, made possible by the independent blinking events of the individual particles. Discrete steps in the localization are observed as random switching between various on/off configurations moves the location of the emission center.

  16. Magnetic resonance imaging of nasopharyngeal carcinoma. Correlation with otitis media with effusion (OME)

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Y.; Tamaki, S.; Kurata, K.; Honjo, I.; Nishimura, K.; Nakano, Y.

    1987-04-01

    Magnetic resonance imaging (MRI) of the nasopharynx, the eustachian tube and the middle ear was performed in nine patients with nasopharyngeal carcinoma. MRI revealed the extent of the tumor more clearly than CT (computed tomography) when the tumor was situated in the parapharyngeal space. But when the tumor extended superficially in the nasopharyngeal mucosa, its margin could not be identified clearly by either MRI or CT because of hypervascularity and long T1 and T2 of the nasopharyngeal mucosa. Seven of the nine patients had unilateral otitis media with effusion. Their eustachian tube ventilation function was evaluated by an inflation-deflation technique. Failure of active equalization of negative pressure applied to the middle ear was found to be a characteristic disorder of their eustachian tube ventilation function. This dysfunction seemed to be correlated with the lateral dislocation of the eustachian tube cartilage caused by the tumor.

  17. Stress and structural damage sensing piezospectroscopic coatings validated with digital image correlation

    Directory of Open Access Journals (Sweden)

    Gregory Freihofer

    2015-03-01

    Full Text Available The piezospectroscopic effect, relating a material’s stress state and spectral signature, has recently demonstrated tailorable sensitivity when the photo-luminescent alpha alumina is distributed in nanoparticulate form within a matrix. Here, the stress-sensing behavior of an alumina-epoxy nanoparticle coating, applied to a composite substrate in an open hole tension configuration, is validated with the biaxial strain field concurrently determined through digital image correlation. The coating achieved early detection of composite failure initiation at 77% failure load, and subsequently tracked stress distribution in the immediate vicinity of the crack as it progressed, demonstrating non-invasive stress and damage detection with multi-scale spatial resolution.

  18. Identification of the elastic stiffness of composites using the virtual fields method and digital image correlation

    Science.gov (United States)

    Jiang, Lebin; Guo, Baoqiao; Xie, Huimin

    2015-04-01

    This paper presents an effective methodology for characterizing the mechanical parameters of composites using digital image correlation combined with the virtual fields method. By using a three-point bending test configuration, this method can identify all mechanical parameters of the material with merely a single test. Successful results verified that this method is especially effective for characterizing composite materials. In this study, the method is applied to measure the orthotropic elastic parameters of fiber-reinforced polymer-matrix composites before and after the hygrothermal aging process. The results indicate that the hygrothermal aging environment significantly influences the mechanical property of a composite. The components of the parameters in the direction of the fiber bundle decreased significantly. From the accuracy analysis, we found that the actual measurement accuracy is sensitive to a shift of the horizontal edges and rotation of the vertical edges.

  19. Applying partial correlation method to analyzing the correlation between ionospheric NmF2 and height of isobaric level in the lower atmosphere

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of a multiple linear regression model performed for ionospheric NmF2, partial correlation method is first applied to investigating the relation between NmF2 and h (the height of isobaric level) in the lower atmosphere over Wuhan, China during 1957―2004. The results show that partial correlation method can eliminate the influences of solar and geomagnetic activities as well as the seasonal variation factors and reveal the true correlation between NmF2 and h in the lower atmosphere. A weak positive correlation between NmF2 and h is found in the middle stratosphere. In addition, by comparing the partial correlation coefficients between NmF2 and its influence factors, we find that NmF2 is mainly affected by solar activity and the seasonal variation factors, and weakly affected by geomagnetic activity, but hardly affected by h in the lower atmosphere. The study suggests that partial correlation method is a helpful tool for investigating the correlation between ionospheric parameter and its influence factors.

  20. Vector Velocity Imaging Using Cross-Correlation and Virtual Sources

    DEFF Research Database (Denmark)

    Holfort, Iben Kraglund; Kortbek, Jacob; Jensen, Jørgen Arendt

    2006-01-01

    Previous investigations have shown promising results in using the directional cross-correlation method to estimate velocity vectors. The velocity vector estimate provides information on both velocity direction and magnitude. The direction is estimated by beamforming signals along directions...

  1. Iterative cross-correlation analysis of resting state functional magnetic resonance imaging data.

    Directory of Open Access Journals (Sweden)

    Liqin Yang

    Full Text Available Seed-based cross-correlation analysis (sCCA and independent component analysis have been widely employed to extract functional networks from the resting state functional magnetic resonance imaging data. However, the results of sCCA, in terms of both connectivity strength and network topology, can be sensitive to seed selection variations. ICA avoids the potential problems due to seed selection, but choosing which component(s to represent the network of interest could be subjective and problematic. In this study, we proposed a seed-based iterative cross-correlation analysis (siCCA method for resting state brain network analysis. The method was applied to extract default mode network (DMN and stable task control network (STCN in two independent datasets acquired from normal adults. Compared with the networks obtained by traditional sCCA and ICA, the resting state networks produced by siCCA were found to be highly stable and independent on seed selection. siCCA was used to analyze DMN in first-episode major depressive disorder (MDD patients. It was found that, in the MDD patients, the volume of DMN negatively correlated with the patients' social disability screening schedule scores.

  2. Joint transform correlator fingerprint verification using complementary-reference and complementary-scene images

    Science.gov (United States)

    Kamal, Hussain A.; Cherri, Abdallah K.

    2009-04-01

    Being a popular choice among the biometric features, the fingerprint has long been used for identification and verification purposes by security agencies. In this paper, additional images are included in the input joint images in a joint transform correlator (JTC) to achieve a fast real-time fingerprint verification. In the proposed scheme, in addition to the reference and the target image, the input joint image has a complementary reference image and a complementary target image. At the correlation output of the JTC, the cross-correlation peak value between the reference and the complementary target image and the cross-correlation peak value between the complementary reference and the target images are used as the criteria to perform the recognition of the target in the input scene. It will be shown that these two cross-correlation peak values will be zero if and only if the input target matches the reference image. The scheme is employed to verify binary characters and binarized fingerprint images.

  3. Evaluation of icing drag coefficient correlations applied to iced propeller performance prediction

    Science.gov (United States)

    Miller, Thomas L.; Shaw, R. J.; Korkan, K. D.

    1987-01-01

    Evaluation of three empirical icing drag coefficient correlations is accomplished through application to a set of propeller icing data. The various correlations represent the best means currently available for relating drag rise to various flight and atmospheric conditions for both fixed-wing and rotating airfoils, and the work presented here ilustrates and evaluates one such application of the latter case. The origins of each of the correlations are discussed, and their apparent capabilities and limitations are summarized. These correlations have been made to be an integral part of a computer code, ICEPERF, which has been designed to calculate iced propeller performance. Comparison with experimental propeller icing data shows generally good agreement, with the quality of the predicted results seen to be directly related to the radial icing extent of each case. The code's capability to properly predict thrust coefficient, power coefficient, and propeller efficiency is shown to be strongly dependent on the choice of correlation selected, as well as upon proper specificatioon of radial icing extent.

  4. Correlation energies beyond the random-phase approximation: ISTLS applied to spherical atoms and ions

    CERN Document Server

    Gould, Tim

    2012-01-01

    The inhomogeneous Singwi, Tosi, Land and Sjolander (ISTLS) correlation energy functional of Dobson, Wang and Gould [PRB {\\bf 66} 081108(R) (2008)] has proved to be excellent at predicting correlation energies in semi-homogeneous systems, showing promise as a robust `next step' fifth-rung functional by using dynamic correlation to go beyond the limitations of the direct random-phase approximation (dRPA), but with similar numerical scaling with system size. In this work we test the functional on fourteen spherically symmetric, neutral and charged atomic systems and find it gives excellent results (within 2mHa/$e^-$ except Be) for the absolute correlation energies of the neutral atoms tested, and good results for the ions (within 4mHa/$e^-$). In all cases it performs better than the dRPA. When combined with the previous successes, these new results point to the ISTLS functional being a prime contender for high-accuracy, benchmark DFT correlation energy calculations.

  5. On the correlation between magnetoacoustic emission and magnetostriction dependence on the applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowski, Leszek; Chmielewski, Marek; Augustyniak, Bolesław

    2016-07-15

    The correlation between magnetoacoustic emission signal envelopes and magnetostriction curves is investigated. Two sets of samples are being considered: tempered martensitic steel and plastically deformed ferritic steel. It is shown that even though some general relations may be observed, as was demonstrated in the literature, the correlation is not always present. One may not expect to change both quantities in the same way if a serious modification of microstructure takes place, as for instance in the case of plastically deformed samples for which the dislocation cell structure is formed once a certain level (1.5–2%) of deformation is reached. Being so, any relation not taking into account statistical properties of domain structure and pinning sites distribution may not yield a general solution of the problem. - Highlights: • Correlation between magnetoacoustic emission and magnetostriction is investigated. • Both MAE and elongation rate are dependent on the non-180° domain walls movement. • Heat treatment affects both phenomena in a similar way. • For plastic deformation, such a correlation is lost. • The correlation is present only if there is no strong change of the microstructure.

  6. Correlation of MR Perfusion-weighted Imaging of Prostatic Cancer with Tumor Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-bin; SHEN Jun-kang; XU Jian-ming; LI Xiao-bing

    2008-01-01

    Objective:MR perfusion-weighted imaging(PWI)has been widely applied in the research of cerebral tumor,benign and malignant musculoskeletal neoplasms and so on.The aim of this study is to explore the application of MR perfusion-weighted imaging in prostatic cancer(Pca),and evaluate the correlation of PWI features with vascular endothelial growth factor (VEGF)and microvessel density(MVD).Methods:Twenty-eight consecutive patients who were diagnosed clinically as prostatic cancer and thirty healthy volunteers were examined by PWI.MVD and VEGF were stained with immunohistochemical methods.Some parameters of PWI,including the steepest slope of signal intensity-time curve(SSmax)and the change in relaxation rate(△R2*peak)at lesions,were analyzed.Correlation analysis was used to determine the relationship between the results of PWI and that of immunohistochemistry.Results:(1)In the healthy volunteers.the steepest slope of signal intensity-time curve(SSmax)and △R2*peak of perfusion curve were;0.430±0.011,2.01±0.7 respectively;however,in the prostatic caucer,they were 57.8±5.0,3.0±0.6 respectively;with significant difference(t=4.11,3.28,P<0.01).(2)The VEGF and MVD expression of twenty-eight Pca patients were significantly higher.Conclusion:On MR perfusion.weighted imaging,SSmax and △R2*peak Can reflect MVD and VEGF expression levels in prostatic cancer.suggesting information on tumor angiogenesis.Thus they are beneficial to the diagnosis and treatment of prostatic cancer.

  7. Correlation between subjective and objective assessment of magnetic resonance (MR) images.

    Science.gov (United States)

    Chow, Li Sze; Rajagopal, Heshalini; Paramesran, Raveendran

    2016-07-01

    Medical Image Quality Assessment (IQA) plays an important role in assisting and evaluating the development of any new hardware, imaging sequences, pre-processing or post-processing algorithms. We have performed a quantitative analysis of the correlation between subjective and objective Full Reference - IQA (FR-IQA) on Magnetic Resonance (MR) images of the human brain, spine, knee and abdomen. We have created a MR image database that consists of 25 original reference images and 750 distorted images. The reference images were distorted with six types of distortions: Rician Noise, Gaussian White Noise, Gaussian Blur, DCT compression, JPEG compression and JPEG2000 compression, at various levels of distortion. Twenty eight subjects were chosen to evaluate the images resulting in a total of 21,700 human evaluations. The raw scores were then converted to Difference Mean Opinion Score (DMOS). Thirteen objective FR-IQA metrics were used to determine the validity of the subjective DMOS. The results indicate a high correlation between the subjective and objective assessment of the MR images. The Noise Quality Measurement (NQM) has the highest correlation with DMOS, where the mean Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are 0.936 and 0.938 respectively. The Universal Quality Index (UQI) has the lowest correlation with DMOS, where the mean PLCC and SROCC are 0.807 and 0.815 respectively. Student's T-test was used to find the difference in performance of FR-IQA across different types of distortion. The superior IQAs tested statistically are UQI for Rician noise images, Visual Information Fidelity (VIF) for Gaussian blur images, NQM for both DCT and JPEG compressed images, Peak Signal-to-Noise Ratio (PSNR) for JPEG2000 compressed images.

  8. Correlation Analysis of TEM Images of Nanocrystal Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Micheel, Christine; Zanchet, Daniele; Alivisatos, A. Paul

    2008-05-21

    Quantitative characterizataion of images of naocrystals and nanostructures is a challenging but important task. The development and optimization of methods for the construction of complex nanostructures rely on imaging techniques. Computer programs were developed to quantify TEM images of nanocrystal/DNA nanostructures, and results are presented for heterodimers annd trimers of gold nanocrystals. The programs presented here have also been used to analyze more complex trimers and tetramers linked by branched DNA, as well as for structures made from attaching gold nanocrystals to CdSe/ZnS core-shell quantum dots. This work has the additional goal of enabling others to quickly and easily adapt the methods for their own use.

  9. Mesenchymal hamartoma of liver: Magnetic resonance imaging and histopathologic correlation

    Institute of Scientific and Technical Information of China (English)

    Bin-Bin Ye; Bing Hu; Li-Jun Wang; Hong-Sheng Liu; Yan Zou; Yu-Bin Zhou; Zhuang Kang

    2005-01-01

    AIM: To describe the imaging features of hepatic mesenchymal hamartoma with emphasis on magnetic resonance imaging (MRI) compared to histopathologic results.METHODS: Spin-echo sequence(SE),fast spin-echo sequence(FSE) were detected in 12 children (7 males, 5 females) with mesenchymal hamartoma of the liver (MHL), aged 1.2 months to 12 years,( mean age, 6.3 years) by axial, saggital, coronary plain imaging with an Elscint 2.0T MR equipment. Their main symptoms were abdominal mass (5 cases), enlarged liver (8 cases), abdominal pain (1 case) and anemia (2 cases),and negative alpha-fetoprotein. Dynamic enhancement examination was added in 2 cases.RESULTS: Six cases had single mass type of MHL, in which 3 cases had solid masses showing slight low-signal-intensity in T1WI, and irregular high-signal-intensity in T2WI, 1 case had a cystic-solid mixed mass showing several border-clear cysts in a solid mass, 2 cases had cystic masses with multi-septa. Five cases had diffuse and multifocal lesions type of MHL with its signal intensity being similar to that of the solid mass. One case had a combined diffuse and single cystic mass. In the early dynamic enhancement examination, the lesions were slightly circum-enhanced, and the center was enhanced in the later scan images. Inner hepatic vessels were compressed in 5 cases, vena cava and abdominal aortae were compressed in 3 cases. Pathological findings included fiber hyperplasia, hyaline degeneration, biliary duct hyperplasia, lobule-like array.CONCLUSION: MR imaging is a better way to differentiate and diagnose MHL. MHL may be recognized by its characteristic occurrence in infancy and MR imaging features.

  10. Digital Image Correlation of Flapping Wings for Micro-Technologies

    Science.gov (United States)

    2011-08-01

    and have served as a tutor for grade school students. I enjoy playing the tuba in the Georgia Tech Pep Band, playing classical piano , reading science...alternative that can be temporary, faster, and less expensive. DIC is a displacement measuring technique that uses a large number of images that are taken

  11. NDVI and Panchromatic Image Correlation Using Texture Analysis

    Science.gov (United States)

    2010-03-01

    18 Equation 4. Equations of the eight GLCM texture features (After Shi, 2003)....................21 Equation 5...analysis and image classification like the Grey Level Co-occurrence Matrix ( GLCM ) by Haralick, 1973. First-order and second-order texture measures on... GLCM consist of Standard Deviation, Range, Minimum, Maximum and Mean. The second order of texture measures includes Angular Second Moment, Contrast

  12. Two-dimensional optical correlation spectroscopy applied to liquid/glass dynamics

    NARCIS (Netherlands)

    Lazonder, Kees; Pshenichnikov, Maxim S.; Wiersma, Douwe A.

    2006-01-01

    Correlation spectroscopy was used to study the effects of temperature and phase changes on liquid and glass solvent dynamics. This method yielded both intuitive clues and a quantitative measure of the dynamics of the system. © 2006 Optical Society of America.

  13. Correlation analysis-based image segmentation approach for automatic agriculture vehicle

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    It is important to segment image correctly to extract guidance information for automatic agriculture vehicle. If we can make the computer know where the crops are, we can extract the guidance line easily. Images were divided into some rectangle small windows, then a pair of 1-D arrays was constructed in each small windows. The correlation coefficients of every small window constructed the features to segment images. The results showed that correlation analysis is a potential approach for processing complex farmland for guidance system, and more correlation analysis methods must be researched.

  14. Applying big data technologies in the financial sector – using sentiment analysis to identify correlations in the stock market

    Directory of Open Access Journals (Sweden)

    Eszter Katalin Bognár

    2016-06-01

    Full Text Available The aim of this article is to introduce a system that is capable of collecting and analyzing different types of financial data to support traders in their decision - making. Oracle’s Big Data platform Oracle Advanced Analytics was utilized, which extends the Oracle Database with Oracle R, thus providing the opportunity to run embedded R scripts on the database server to speed up data processing. The extract, transform and load (ETL process was combined with a dictionary - based sentiment analysis module to examine cross - correlation and causality between numerical and textual financial data for a 10 week period. A notable correlation (0.42 was found between daily news sentiment scores and daily stock returns. By applying cross - correlation analysis and Granger causality testing, the results show that the news’ impact is incorporated into stock prices rapidly, having the highest correlation on the first day, while the returns’ impact on market sentiment is seen only after a few days.

  15. Pattern recognition applied to infrared images for early alerts in fog

    Science.gov (United States)

    Boucher, Vincent; Marchetti, Mario; Dumoulin, Jean; Cord, Aurélien

    2014-09-01

    Fog conditions are the cause of severe car accidents in western countries because of the poor induced visibility. Its forecast and intensity are still very difficult to predict by weather services. Infrared cameras allow to detect and to identify objects in fog while visibility is too low for eye detection. Over the past years, the implementation of cost effective infrared cameras on some vehicles has enabled such detection. On the other hand pattern recognition algorithms based on Canny filters and Hough transformation are a common tool applied to images. Based on these facts, a joint research program between IFSTTAR and Cerema has been developed to study the benefit of infrared images obtained in a fog tunnel during its natural dissipation. Pattern recognition algorithms have been applied, specifically on road signs which shape is usually associated to a specific meaning (circular for a speed limit, triangle for an alert, …). It has been shown that road signs were detected early enough in images, with respect to images in the visible spectrum, to trigger useful alerts for Advanced Driver Assistance Systems.

  16. Efficient super-resolution image reconstruction applied to surveillance video captured by small unmanned aircraft systems

    Science.gov (United States)

    He, Qiang; Schultz, Richard R.; Chu, Chee-Hung Henry

    2008-04-01

    The concept surrounding super-resolution image reconstruction is to recover a highly-resolved image from a series of low-resolution images via between-frame subpixel image registration. In this paper, we propose a novel and efficient super-resolution algorithm, and then apply it to the reconstruction of real video data captured by a small Unmanned Aircraft System (UAS). Small UAS aircraft generally have a wingspan of less than four meters, so that these vehicles and their payloads can be buffeted by even light winds, resulting in potentially unstable video. This algorithm is based on a coarse-to-fine strategy, in which a coarsely super-resolved image sequence is first built from the original video data by image registration and bi-cubic interpolation between a fixed reference frame and every additional frame. It is well known that the median filter is robust to outliers. If we calculate pixel-wise medians in the coarsely super-resolved image sequence, we can restore a refined super-resolved image. The primary advantage is that this is a noniterative algorithm, unlike traditional approaches based on highly-computational iterative algorithms. Experimental results show that our coarse-to-fine super-resolution algorithm is not only robust, but also very efficient. In comparison with five well-known super-resolution algorithms, namely the robust super-resolution algorithm, bi-cubic interpolation, projection onto convex sets (POCS), the Papoulis-Gerchberg algorithm, and the iterated back projection algorithm, our proposed algorithm gives both strong efficiency and robustness, as well as good visual performance. This is particularly useful for the application of super-resolution to UAS surveillance video, where real-time processing is highly desired.

  17. Motion de-blurring by second-order intensity-correlated imaging

    Institute of Scientific and Technical Information of China (English)

    Zunwang Bo; Wenlin Gong; Shensheng Han

    2016-01-01

    For a Hanbury Brown and Twiss system,the influence of relative motion between the object and the detection plane on the resolution of second-order intensity-correlated imaging is investigated.The analytical results,which are backed up by experiments,demonstrate that the amplitude and mode of the object's motion have no effect on the second-order intensity-correlated imaging and that high-resolution imaging can be always achieved by using a phase-retrieval method from the diffraction patterns.The use of motion de-blurring imaging for this approach is also discussed.

  18. Hip arthropathy in a patient with primary hemochromatosis: MR imaging findings with pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Papakonstantinou, Olympia [Veterans Affairs Medical Center, University of California, Department of Radiology, San Diego (United States); University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); Mohana-Borges, Aurea V.R.; Campell, Loretta; Trudell, Debra; Resnick, Donald [Veterans Affairs Medical Center, University of California, Department of Radiology, San Diego (United States); Haghighi, Parviz [Veterans Affairs Medical Center, University of California, Department of Pathology, San Diego, California (United States)

    2005-03-01

    Arthropathy is a major clinical manifestation in primary hemochromatosis, typically affecting the metacarpophalangeal joints. Hip arthropathy is not uncommon, with radiologic features resembling osteoarthritis or calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. We describe the MR imaging findings of the hip in a patient with severe hip arthropathy and primary hemochromatosis and correlate them with the histopathologic findings. MR imaging showed severe degenerative changes, with large subchondral cysts and subchondral sclerosis in the femoral head and acetabulum. There was conspicuous correlation between MR imaging and pathologic findings of the resected femoral head. However, MR imaging failed to reveal intra-articular iron. (orig.)

  19. Detection of correlated fragments in a sequence of images by superimposed Fourier holograms

    Science.gov (United States)

    Pavlov, A. V.

    2016-08-01

    The problem of detecting correlated fragments in a sequence of images recorded by the superimposing holograms within the Fourier holography scheme with angular multiplication of a spatially modulated reference beam is considered. The approach to the solution of this problem is based on the properties of the variance of the image sum. It is shown that this problem can be solved by providing a constant distance between the signal and reference images when recording superimposed holograms and a partial mutual correlatedness of reference images. The detection efficiency is analysed from the point of view of estimated image data capacity, the degree of mutual correlation of reference images, and the hologram recording conditions. The results of a numerical experiment under the most complicated conditions (representation of images by realisations of homogeneous random fields) confirm the theoretical conclusions.

  20. Versatile quantitative phase imaging system applied to high-speed, low noise and multimodal imaging (Conference Presentation)

    Science.gov (United States)

    Federici, Antoine; Aknoun, Sherazade; Savatier, Julien; Wattellier, Benoit F.

    2017-02-01

    Quadriwave lateral shearing interferometry (QWLSI) is a well-established quantitative phase imaging (QPI) technique based on the analysis of interference patterns of four diffraction orders by an optical grating set in front of an array detector [1]. As a QPI modality, this is a non-invasive imaging technique which allow to measure the optical path difference (OPD) of semi-transparent samples. We present a system enabling QWLSI with high-performance sCMOS cameras [2] and apply it to perform high-speed imaging, low noise as well as multimodal imaging. This modified QWLSI system contains a versatile optomechanical device which images the optical grating near the detector plane. Such a device is coupled with any kind of camera by varying its magnification. In this paper, we study the use of a sCMOS Zyla5.5 camera from Andor along with our modified QWLSI system. We will present high-speed live cell imaging, up to 200Hz frame rate, in order to follow intracellular fast motions while measuring the quantitative phase information. The structural and density information extracted from the OPD signal is complementary to the specific and localized fluorescence signal [2]. In addition, QPI detects cells even when the fluorophore is not expressed. This is very useful to follow a protein expression with time. The 10 µm spatial pixel resolution of our modified QWLSI associated to the high sensitivity of the Zyla5.5 enabling to perform high quality fluorescence imaging, we have carried out multimodal imaging revealing fine structures cells, like actin filaments, merged with the morphological information of the phase. References [1]. P. Bon, G. Maucort, B. Wattellier, and S. Monneret, "Quadriwave lateral shearing interferometry for quantitative phase microscopy of living cells," Opt. Express, vol. 17, pp. 13080-13094, 2009. [2] P. Bon, S. Lécart, E. Fort and S. Lévêque-Fort, "Fast label-free cytoskeletal network imaging in living mammalian cells," Biophysical journal, 106

  1. On the correlation between magnetoacoustic emission and magnetostriction dependence on the applied magnetic field

    Science.gov (United States)

    Piotrowski, Leszek; Chmielewski, Marek; Augustyniak, Bolesław

    2016-07-01

    The correlation between magnetoacoustic emission signal envelopes and magnetostriction curves is investigated. Two sets of samples are being considered: tempered martensitic steel and plastically deformed ferritic steel. It is shown that even though some general relations may be observed, as was demonstrated in the literature, the correlation is not always present. One may not expect to change both quantities in the same way if a serious modification of microstructure takes place, as for instance in the case of plastically deformed samples for which the dislocation cell structure is formed once a certain level (1.5-2%) of deformation is reached. Being so, any relation not taking into account statistical properties of domain structure and pinning sites distribution may not yield a general solution of the problem.

  2. Cystic synovial sarcomas: imaging features with clinical and histopathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Hirofumi; Araki, Nobuhito [Department of Orthopedic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3, Nakamichi, Higashinari-Ku, 537-8511, Osaka (Japan); Sawai, Yuka [Department of Radiology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Kudawara, Ikuo [Department of Orthopedic Surgery, Osaka National Hospital, Osaka (Japan); Mano, Masayuki; Ishiguro, Shingo [Department of Pathology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ueda, Takafumi; Yoshikawa, Hideki [Department of Orthopedic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka (Japan)

    2003-12-01

    To characterize the radiological and clinicopathologic features of cystic synovial sarcoma. Seven patients with primary cystic synovial sarcoma were evaluated. Computed tomography (CT) and magnetic resonance (MR) imaging were undertaken at the first presentation. The diagnosis of synovial sarcoma was made on the basis of histological examinations followed by molecular analysis. Radiological and clinicopathologic findings were reviewed. CT showed well-defined soft tissue mass without cortical bone erosion and invasion. Calcification was seen at the periphery of the mass in three cases. T2-weighted MR images showed multilocular inhomogeneous intensity mass in all cases, five of which showed fluid-fluid levels. On gross appearance, old and/or fresh hematomas were detected in six cases. In the one remaining case, microscopic hemorrhage in the cystic lumen was proven. Four cases had poorly differentiated areas. In five cases prominent hemangiopericytomatous vasculature was observed. Histologic grade was intermediate in one tumor and high in six. One case had a history of misdiagnosis for tarsal tunnel syndrome, one for lymphadenopathy, two for sciatica and two for hematoma. All cystic synovial sarcomas demonstrated multilocularity with well-circumscribed walls and internal septae. Synovial sarcoma should be taken into consideration in patients with deeply situated multicystic mass with triple signal intensity on T2-weighted MR imaging. (orig.)

  3. Renal cell carcinoma: histological classification and correlation with imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Muglia, Valdair F., E-mail: fmuglia@fmrp.usp.br [Universidade de Sao Paulo (CCIFM/FMRP/USP), Ribeirao Preto, SP (Brazil). Centro de Ciencias das Imagens e Fisica Medica. Faculdade de Medicina; Prando, Adilson [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Hospital Vera Cruz, Campinas, SP (Brazil). Dept. de Imaginologia

    2015-05-15

    Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes. (author)

  4. Nanoparticle flow velocimetry with image phase correlation for confocal laser scanning microscopy

    Science.gov (United States)

    Jun, Brian H.; Giarra, Matthew; Yang, Haisheng; Main, Russell; Vlachos, Pavlos P.

    2016-10-01

    We present a new particle image correlation technique for resolving nanoparticle flow velocity using confocal laser scanning microscopy (CLSM). The two primary issues that complicate nanoparticle scanning laser image correlation (SLIC)-based velocimetry are (1) the use of diffusion-dominated nanoparticles as flow tracers, which introduce a random decorrelating error into the velocity estimate, and (2) the effects of the scanning laser image acquisition, which introduces a bias error. To date, no study has quantified these errors or demonstrated a means to deal with them in SLIC velocimetry. In this work, we build upon the robust phase correlation (RPC) and existing methods of SLIC to quantify and mitigate these errors. First, we implement an ensemble RPC instead of using an ensemble standard cross-correlation, and develop a SLIC optimal filter that maximizes the correlation strength in order to reliably and accurately detect the correlation peak representing the most probable average displacement of the nanoparticles. Secondly, we developed an analytical model of the SLIC measurement bias error due to image scanning of diffusion-dominated tracer particles. We show that the bias error depends only on the ratio of the mean velocity of the tracer particles to that of the laser scanner and we use this model to correct the induced errors. We validated our technique using synthetic images and experimentally obtained SLIC images of nanoparticle flow through a micro-channel. Our technique reduced the error by up to a factor of ten compared to other SLIC algorithms for the images tested in this study. Moreover, our optimized RPC filter reduces the number of image pairs required for the convergence of the ensemble correlation by two orders of magnitude compared to the standard cross correlation. This feature has broader implications to ensemble correlation methods and should be further explored in depth in the future.

  5. Improving Prediction Accuracy for WSN Data Reduction by Applying Multivariate Spatio-Temporal Correlation

    Directory of Open Access Journals (Sweden)

    José Neuman de Souza

    2011-10-01

    Full Text Available This paper proposes a method based on multivariate spatial and temporal correlation to improve prediction accuracy in data reduction for Wireless Sensor Networks (WSN. Prediction of data not sent to the sink node is a technique used to save energy in WSNs by reducing the amount of data traffic. However, it may not be very accurate. Simulations were made involving simple linear regression and multiple linear regression functions to assess the performance of the proposed method. The results show a higher correlation between gathered inputs when compared to time, which is an independent variable widely used for prediction and forecasting. Prediction accuracy is lower when simple linear regression is used, whereas multiple linear regression is the most accurate one. In addition to that, our proposal outperforms some current solutions by about 50% in humidity prediction and 21% in light prediction. To the best of our knowledge, we believe that we are probably the first to address prediction based on multivariate correlation for WSN data reduction.

  6. Diffusion-relaxation correlation spectroscopic imaging: A multidimensional approach for probing microstructure.

    Science.gov (United States)

    Kim, Daeun; Doyle, Eamon K; Wisnowski, Jessica L; Kim, Joong Hee; Haldar, Justin P

    2017-03-19

    To propose and evaluate a novel multidimensional approach for imaging subvoxel tissue compartments called Diffusion-Relaxation Correlation Spectroscopic Imaging. Multiexponential modeling of MR diffusion or relaxation data is commonly used to infer the many different microscopic tissue compartments that contribute signal to macroscopic MR imaging voxels. However, multiexponential estimation is known to be difficult and ill-posed. Observing that this ill-posedness is theoretically reduced in higher dimensions, diffusion-relaxation correlation spectroscopic imaging uses a novel multidimensional imaging experiment that jointly encodes diffusion and relaxation information, and then uses a novel constrained reconstruction technique to generate a multidimensional diffusion-relaxation correlation spectrum for every voxel. The peaks of the multidimensional spectrum are expected to correspond to the distinct tissue microenvironments that are present within each macroscopic imaging voxel. Using numerical simulations, experiment data from a custom-built phantom, and experiment data from a mouse model of traumatic spinal cord injury, diffusion-relaxation correlation spectroscopic imaging is demonstrated to provide substantially better multicompartment resolving power compared to conventional diffusion- and relaxation-based methods. The diffusion-relaxation correlation spectroscopic imaging approach provides powerful new capabilities for resolving the different components of multicompartment tissue models, and can be leveraged to significantly expand the insights provided by MRI in studies of tissue microstructure. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  7. Are planets and debris correlated? Herschel imaging of 61 Vir.

    Science.gov (United States)

    Wyatt, M.; Kennedy, G. M.; Moro-Martín, A.

    2012-03-01

    Debris disk studies with Spitzer found no evidence of a correlation between (giant) exoplanets and circumsteallar dust. Since these studies were carried out, a new parameter space of fainter and colder debris disks has been opened up by the Herschel Space Observatory -- improving our knowledge of the disk frequency, in particular around cooler stars -- and simultaneously higher precision doppler surveys have allowed the detection of lower-mass planets, the frequency of which can now be characterized.Ê Here, we revisit the planet-debris disk correlation using Herschel data from the DEBRIS and DUNES surveys. We assess whether the frequency and properties of disks around stars with high-mass and low-mass planets are any different from a control sample, and if these differences can be used to shed light on planet formation mechanisms and to ÒpredictÓ the presence of planets around stars with certain disk characteristics.

  8. Parallax Measurement Using an Image Matched Filter Correlator

    Science.gov (United States)

    1975-04-01

    was also necessary to isolate the laser by installing rubber pads under it and by suspending the umbilical cord in order to eliminate vibrations...mirror. This assembly tended to vibrate and it proved necessary to remove it and replace the small mirror by a larger mirror clamped directly to...where a ^ b. Consider the situation in Figure A-l where a hologram is re- corded in plane H. The correlations are formed by lens Lj in

  9. On the loss-of-correlation due to PIV image noise

    Science.gov (United States)

    Scharnowski, Sven; Kähler, Christian J.

    2016-07-01

    The effect of image noise on the uncertainty of velocity fields measured with particle image velocimetry (PIV) is still an unsolved problem. Image noise reduces the correlation signal and thus affects the estimation of the particle image displacement. However, a systematic quantification of the effect of the noise level on the loss-of-correlation is missing. In this work, a new method is proposed to estimate the loss-of-correlation due to image noise F_{σ } from the autocorrelation function of PIV images. Furthermore, a new definition of the signal-to-noise ratio (SNR) for PIV images is suggested, which results in a bijective relation between F_{σ } and SNR. Based on the newly defined SNR, it becomes possible to estimate the signal level and the noise level itself. The presented method is very general because the estimation of F_{σ } and SNR works independently of various parameters, including the particle image intensity, the particle image density, the particle image size, the image noise distributions and the laser light-sheet profile. The findings lead to an extension of the fundamental PIV equation N=NI FI FO F_{Δ } and enable PIV users to optimize their measurement setup with respect to the image noise and not only based on the loss-of-correlation due to in-plane motion, out-of-plane motion and displacement gradients. Furthermore, the new definition of SNR allows for a characterization and comparison of PIV images. The new approaches are validated by using synthetic images, and the predictions are confirmed by using experimental data.

  10. Contrast-enhanced breast ultrasonography: imaging features with histopathologic correlation.

    Science.gov (United States)

    Liu, He; Jiang, Yu-Xin; Liu, Ji-Bin; Zhu, Qing-Li; Sun, Qiang; Chang, Xiao-Yan

    2009-07-01

    The purpose of this study was to identify histopathologic correlates for the varied appearances of breast masses on contrast-enhanced ultrasonography (CEUS). Contrast-enhanced ultrasonography was performed in 104 patients (age range, 19-86 years) after administration of a sulfur hexafluoride microbubble contrast agent, and enhancement patterns were classified as no enhancement, peripheral enhancement, homogeneous enhancement, regional enhancement, and heterogeneous enhancement. All patients' histologic slides were reviewed and correlated with CEUS findings. In malignant masses, heterogeneous enhancement corresponded to tumor cell cords or clusters in a variable amount of desmoplastic stroma. Homogeneous enhancement corresponded to hypercellularity in the whole mass, or ductal carcinoma in situ (DCIS) was predominant. Regional enhancement corresponded to a DCIS component. Peripheral enhancement corresponded to a DCIS component, hypercellularity or adenosis at the periphery, and low-degree cellularity, degeneration, fibrosis, or necrosis in the center. No enhancement was present in 1 case of low-grade DCIS. In benign masses, heterogeneous enhancement corresponded to loose cell proliferation in a more sclerotic stroma. Homogeneous enhancement corresponded to diffuse hypercellularity, an inflammatory cell infiltrate, or intraductal papilloma. Regional enhancement corresponded to focal hypercellularity or intraductal papilloma within a dilated duct. No enhancement corresponded to desmoplastic stroma. Peripheral enhancement was shown in 1 case of granulomatous mastitis with an inflammatory infiltrate at the periphery and necrosis in the center. Breast mass CEUS findings correlated with histologic features.

  11. 3D fast adaptive correlation imaging for large-scale gravity data based on GPU computation

    Science.gov (United States)

    Chen, Z.; Meng, X.; Guo, L.; Liu, G.

    2011-12-01

    In recent years, large scale gravity data sets have been collected and employed to enhance gravity problem-solving abilities of tectonics studies in China. Aiming at the large scale data and the requirement of rapid interpretation, previous authors have carried out a lot of work, including the fast gradient module inversion and Euler deconvolution depth inversion ,3-D physical property inversion using stochastic subspaces and equivalent storage, fast inversion using wavelet transforms and a logarithmic barrier method. So it can be say that 3-D gravity inversion has been greatly improved in the last decade. Many authors added many different kinds of priori information and constraints to deal with nonuniqueness using models composed of a large number of contiguous cells of unknown property and obtained good results. However, due to long computation time, instability and other shortcomings, 3-D physical property inversion has not been widely applied to large-scale data yet. In order to achieve 3-D interpretation with high efficiency and precision for geological and ore bodies and obtain their subsurface distribution, there is an urgent need to find a fast and efficient inversion method for large scale gravity data. As an entirely new geophysical inversion method, 3D correlation has a rapid development thanks to the advantage of requiring no a priori information and demanding small amount of computer memory. This method was proposed to image the distribution of equivalent excess masses of anomalous geological bodies with high resolution both longitudinally and transversely. In order to tranform the equivalence excess masses into real density contrasts, we adopt the adaptive correlation imaging for gravity data. After each 3D correlation imaging, we change the equivalence into density contrasts according to the linear relationship, and then carry out forward gravity calculation for each rectangle cells. Next, we compare the forward gravity data with real data, and

  12. Whole-body diffusion imaging applying simultaneous multi-slice excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kenkel, David; Wurning, M.C.; Filli, L.; Ulbrich, E.J.; Boss, A. [Universitaetsspital Zuerich (Switzerland). Diagnostische und Interventionelle Radiologie; Runge, V.M. [Univ. Hospital Zurich (Switzerland). Dept. of Neuroradiology; Beck, T. [Siemens Healthcare GmbH, Erlangen (Germany)

    2016-04-15

    The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol. A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3 T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale. Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9 %. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol. It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability.

  13. Particle image velocimetry correlation signal-to-noise ratio metrics and measurement uncertainty quantification

    CERN Document Server

    Xue, Zhenyu; Vlachos, Pavlos P

    2014-01-01

    In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations. In addition, the notion of a valid measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct ...

  14. Detection and correction of blinking bias in image correlation transport measurements of quantum dot tagged macromolecules

    DEFF Research Database (Denmark)

    Durisic, Nela; Bachir, Alexia I; Kolin, David L;

    2007-01-01

    Semiconductor nanocrystals or quantum dots (QDs) are becoming widely used as fluorescent labels for biological applications. Here we demonstrate that fluorescence fluctuation analysis of their diffusional mobility using temporal image correlation spectroscopy is highly susceptible to systematic e...

  15. The many faces of pulmonary aspergillosis: Imaging findings with pathologic correlation

    Directory of Open Access Journals (Sweden)

    Prasad Panse

    2016-12-01

    Conclusion: In this article we correlate the radiologic findings of the various pulmonary manifestations of Aspergillus infection with their pathologic features to better understand the disease process and better comprehend the associated imaging patterns.

  16. Large Quantum imaging of nonlocal spatial correlations induced by orbital angular momentum

    CERN Document Server

    Altman, A; Corndorf, E; Kumar, P; Barbosa, G A; Altman, Adam R.; K\\"{o}pr\\"{u}l\\"{u}, Kahraman G.; Corndorf, Eric; Kumar, Prem; Barbosa, Geraldo A.

    2004-01-01

    Through scanned coincidence counting, we probe the quantum image produced by parametric down conversion with a pump beam carrying orbital angular momentum. Nonlocal spatial correlations are manifested through splitting of the coincidence spot into two.

  17. Field methods to measure surface displacement and strain with the Video Image Correlation method

    Science.gov (United States)

    Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.

    1994-01-01

    The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.

  18. Modified digital image correlation for balancing the influence of subset size choice

    Science.gov (United States)

    Li, Bang-Jian; Wang, Quanbao; Duan, Deng-Ping; Chen, Ji-An

    2017-05-01

    A modified digital image correlation (DIC) method is presented to balance the influence of subset size choice, improve the calculation efficiency, and enhance the measurement accuracy. The relations between pixels and the central pixel are investigated. A relatively large subset size is selected in the method and all the pixels in a subset are treated nonuniformly. Weight is assigned to each pixel dependent on the significance of the pixel to track a subset from deformed images, and weights are computed by Butterworth function based on the distances between the pixels and the central pixel in the subset. Compared with classical DIC, the proposed method is a compromise between a small and a large subset. The choice of subset size for classical DIC is displaced by choice of parameters of Butterworth function in the presented method. The influence of subset size is reduced, and the calculation efficiency is improved with enhanced measurement accuracy by the modified method. Computer-simulated speckle patterns and real experiments are applied to verify the proposed method.

  19. A STED-FLIM microscope applied to imaging the natural killer cell immune synapse

    Science.gov (United States)

    Lenz, M. O.; Brown, A. C. N.; Auksorius, E.; Davis, D. M.; Dunsby, C.; Neil, M. A. A.; French, P. M. W.

    2011-03-01

    We present a stimulated emission depletion (STED) fluorescence lifetime imaging (FLIM) microscope, excited by a microstructured optical fibre supercontinuum source that is pumped by a femtosecond Ti:Sapphire-laser, which is also used for depletion. Implemented using a piezo-scanning stage on a laser scanning confocal fluorescence microscope system with FLIM realised using time correlated single photon counting (TCSPC), this provides convenient switching between confocal and STED-FLIM with spatial resolution down to below 60 nm. We will present our design considerations to make a robust instrument for biological applications including a comparison between fixed phase plate and spatial light modulator (SLM) approaches to shape the STED beam and the correlation of STED and confocal FLIM microscopy. Following our previous application of FLIM-FRET to study intercellular signalling at the immunological synapse (IS), we are employing STED microscopy to characterize the spatial distribution of cellular molecules with subdiffraction resolution at the IS. In particular, we are imaging cytoskeletal structure at the Natural Killer cell activated immune synapse. We will also present our progress towards multilabel STED microscopy to determine how relative spatial molecular organization, previously undetectable by conventional microscopy techniques, is important for NK cell cytotoxic function. Keywords: STED, Stimulated Emission Depletion Microscopy, Natural Killer (NK) cell, Fluorescence lifetime imaging, FLIM, Super resolution microscopy.

  20. Correlation of the applied electrical field and CO adsorption/desorption behavior on Al-doped graphene

    Science.gov (United States)

    Ao, Z. M.; Li, S.; Jiang, Q.

    2010-05-01

    Recently, Al-doped graphene was proposed as a highly sensitive CO gas sensor material. In this work, the correlation of the applied electric field F and the adsorption/desorption behavior of a CO molecule on Al-doped graphene was studied by density functional theory calculations. The results indicate that a negative F strengthens the adsorption of the CO on the Al-doped graphene, while the adsorption is reduced when a positive F is present. Furthermore, desorption of the CO molecule from the graphene layer commences when F≥0.03 a.u. is applied, which can be used to reactivate the sensor material for repetitious application.

  1. Analytical shape determination of fiber-like objects with Virtual Image Correlation

    CERN Document Server

    Semin, Benoit; Auradou, Harold

    2010-01-01

    This paper reports a method allowing for the determination of the shape of deformed fiber-like objects. Compared to existing methods, it provides analytical results including the local slope and curvature which are of first importance, for instance, in beam mechanics. The presented VIC (Virtual Image Correlation) method consists in looking for the best correlation between the image of the fiber-like object and a virtual beam image, using an algorithm close to the Digital Image Correlation method developed in experimental solid mechanics. The computation only involves the part of the image in the vicinity of the fiber: the method is thus insensitive to the picture background and the computational cost remains low. Two examples are reported: the first proves the precision of the method, the second its ability to identify a complex shape with multiple loops.

  2. Optical Image Analysis Applied to Pore Network Quantification of Sandstones Under Experimental CO2 Injection

    Science.gov (United States)

    Berrezueta, E.; González, L.; Ordóñez, B.; Luquot, L.; Quintana, L.; Gallastegui, G.; Martínez, R.; Olaya, P.; Breitner, D.

    2015-12-01

    This research aims to propose a protocol for pore network quantification in sandstones applying the Optical Image Analysis (OIA) procedure, which guarantees the measurement reproducibility and its reliability. Two geological formations of sandstone, located in Spain and potentially suitable for CO2 sequestration, were selected for this study: a) the Cretaceous Utrillas unit, at the base of the Cenozoic Duero Basin and b) a Triassic unit at the base of the Cenozoic Guadalquivir Basin. Sandstone samples were studied before and after the CO2 experimental injection using Optical and scanning electronic microscopy (SEM), while the quantification of petrographic changes was done with OIA. The first phase of the rersearch consisted on a detailed mineralogical and petrographic study of the sandstones (before and after CO2-injection), for which we observed thin sections. Later, the methodological and experimental processes of the investigation were focused on i) adjustment and calibration of OIA tools; ii) data acquisition protocol based on image capture with different polarization conditions (synchronized movement of polarizers), using 7 images of the same mineral scene (6 in crossed polarizer and 1 in parallel polarizer); and iii) automated identification and segmentation of pore in 2D mineral images, generating applications by executable macros. Finally, once the procedure protocols had been, the compiled data was interpreted through an automated approach and the qualitative petrography was carried out. The quantification of changes in the pore network through OIA (porosity increase ≈ 2.5%) has allowed corroborate the descriptions obtained by SEM and microscopic techniques, which consisted in an increase in the porosity when CO2 treatment occurs. Automated-image identification and quantification of minerals, pores and textures together with petrographic analysis can be applied to improve pore system characterization in sedimentary rocks. This research offers numerical

  3. Evaluation of correlation between CT image features and ERCC1 protein expression in assessing lung cancer prognosis

    Science.gov (United States)

    Tan, Maxine; Emaminejad, Nastaran; Qian, Wei; Sun, Shenshen; Kang, Yan; Guan, Yubao; Lure, Fleming; Zheng, Bin

    2014-03-01

    Stage I non-small-cell lung cancers (NSCLC) usually have favorable prognosis. However, high percentage of NSCLC patients have cancer relapse after surgery. Accurately predicting cancer prognosis is important to optimally treat and manage the patients to minimize the risk of cancer relapse. Studies have shown that an excision repair crosscomplementing 1 (ERCC1) gene was a potentially useful genetic biomarker to predict prognosis of NSCLC patients. Meanwhile, studies also found that chronic obstructive pulmonary disease (COPD) was highly associated with lung cancer prognosis. In this study, we investigated and evaluated the correlations between COPD image features and ERCC1 gene expression. A database involving 106 NSCLC patients was used. Each patient had a thoracic CT examination and ERCC1 genetic test. We applied a computer-aided detection scheme to segment and quantify COPD image features. A logistic regression method and a multilayer perceptron network were applied to analyze the correlation between the computed COPD image features and ERCC1 protein expression. A multilayer perceptron network (MPN) was also developed to test performance of using COPD-related image features to predict ERCC1 protein expression. A nine feature based logistic regression analysis showed the average COPD feature values in the low and high ERCC1 protein expression groups are significantly different (p study indicates that CT phenotype features are associated with the genetic tests, which may provide supplementary information to help improve accuracy in assessing prognosis of NSCLC patients.

  4. Imaging Three Dimensional Two-Particle Correlations for Heavy-Ion Reaction Studies

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D; Enokizono, A; Heffner, M; Soltz, R; Danielewicz, P; Pratt, S

    2005-06-27

    The authors report an extension of the source imaging method for analyzing three-dimensional sources from three-dimensional correlations. The technique consists of expanding the correlation data and the underlying source function in spherical harmonics and inverting the resulting system of one-dimensional integral equations. With this strategy, they can image the source function quickly, even with the extremely large data sets common in three-dimensional analyses.

  5. Fungal splenic abscesses in the immunosuppressed patient. Correlation of imaging modalities

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, T.E.; Evans, D.G.; Schiffman, H.; Ashburn, W.L.

    1987-01-01

    A patient with fungal splenic abscesses is presented in whom multiple noninvasive diagnostic imaging modalities were available for correlation. Of the five imaging modalities, three (Gallium-67, ultrasound and computed tomography) were diagnostically useful, while two (liver-spleen scan and In-111 white blood cell scan) were not as useful. This case also stresses the use of repeated studies correlating with clinical impressions to obtain an accurate diagnosis in a potentially life-threatening condition such as splenic abscess.

  6. Submaximal delayed-onset muscle soreness: correlations between MR imaging findings and clinical measures

    Science.gov (United States)

    Evans, G. F.; Haller, R. G.; Wyrick, P. S.; Parkey, R. W.; Fleckenstein, J. L.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    PURPOSE: To assess correlations between muscle edema on magnetic resonance (MR) images and clinical indexes of muscle injury in delayed-onset muscle soreness (DOMS) produced by submaximal exercise protocols. MATERIALS AND METHODS: Sixteen subjects performed 36 elbow flexions ("biceps curls") at one of two submaximal workloads that emphasized eccentric contractions. Changes in MR imaging findings, plasma levels of creatine kinase, and pain scores were correlated. RESULTS: Both exercise protocols produced DOMS in all subjects. The best correlation was between change in creatine kinase level and volume of muscle edema on MR images, regardless of the workload. Correlations tended to be better with the easier exercise protocol. CONCLUSION: Whereas many previous studies of DOMS focused on intense exercise protocols to ensure positive results, the present investigation showed that submaximal workloads are adequate to produce DOMS and that correlations between conventionally measured indexes of injury may be enhanced at lighter exercise intensities.

  7. Correlation of diagnostic ultrasound and radionuclide imaging in scrotal disease

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.C.P.; Holder, L.E.; Kaplan, G.N.

    1984-01-01

    A retrospective study was performed to evaluate the usefulness of scrotal ultrasound imaging (SU) and radionuclide scrotal imaging (RSI) in 43 patients (pts), age: 16-75. Twenty-two of them complained of scrotal pain; 18 had a scrotal mass; and 4 had a history of trauma. The final diagnoses were conformed by surgery (n = 21) and long-term follow-up (n = 22) and included 4 late phase and 1 early testicular torsion (TT), 11 acute epididymitis (AE), 4 subacute epididymitis (SE), 5 malignant tumors, 3 testicular atrophy, 2 intratesticular hematomas, 10 hydroceles or other cystic lesions, and miscellaneous. In pts with scrotal pain, 3/4 with late phase TT were correctly diagnosed, while one pt with early TT and 11/15 with AE or SE were not diagnosed by SU. All of them were correctly diagnosed with RSI except one with scrotal cyst. SU was able to separate cystic masses (n = 10) from solid masses (n = 6), but cannot separate malignant from benign lesions. SU was excellent in detecting 19 hydroceles and 2 intratesticular hematomas, while 3 lesions < 1 cm. were not seen in RSI. The authors concluded that SU is useful in pts with scrotal mass to separate solid from cystic lesions. However, SU is unable to differentiate the acute epididymitis from early testicular torsion. In pts with acute scrotal pain, SU is not helpful and RSI should still be the first study performed.

  8. Radiation-Induced Liver Damage: Correlation of Histopathology with Hepatobiliary Magnetic Resonance Imaging, a Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, Max, E-mail: max.seidensticker@med.ovgu.de [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany); Burak, Miroslaw [Pomeranian Medical University, Department of Diagnostic Imaging and Interventional Radiology (Poland); Kalinski, Thomas [Universitätsklinik Magdeburg, Institut für Pathologie (Germany); Garlipp, Benjamin [Universitätsklinik Magdeburg, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie (Germany); Koelble, Konrad [Philipps Universität Marburg, Fachbereich Medizin der, Abteilung für Neuropathologie (Germany); Wust, Peter [Charité Universitätsmedizin Berlin, Klinik für Radioonkologie und Strahlentherapie (Germany); Antweiler, Kai [Universitätsklinik Magdeburg, Institut für Biometrie und Medizinische Informatik (Germany); Seidensticker, Ricarda; Mohnike, Konrad; Pech, Maciej; Ricke, Jens [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany)

    2015-02-15

    PurposeRadiotherapy of liver malignancies shows promising results (radioembolization, stereotactic irradiation, interstitial brachytherapy). Regardless of the route of application, a certain amount of nontumorous liver parenchyma will be collaterally damaged by radiation. The functional reserve may be significantly reduced with an impact on further treatment planning. Monitoring of radiation-induced liver damage by imaging is neither established nor validated. We performed an analysis to correlate the histopathological presence of radiation-induced liver damage with functional magnetic resonance imaging (MRI) utilizing hepatobiliary contrast media (Gd-BOPTA).MethodsPatients undergoing local high-dose-rate brachytherapy for whom a follow-up hepatobiliary MRI within 120 days after radiotherapy as well as an evaluable liver biopsy from radiation-exposed liver tissue within 7 days before MRI were retrospectively identified. Planning computed tomography (CT)/dosimetry was merged to the CT-documentation of the liver biopsy and to the MRI. Presence/absence of radiation-induced liver damage (histopathology) and Gd-BOPTA uptake (MRI) as well as the dose applied during brachytherapy at the site of tissue sampling was determined.ResultsFourteen biopsies from eight patients were evaluated. In all cases with histopathological evidence of radiation-induced liver damage (n = 11), no uptake of Gd-BOPTA was seen. In the remaining three, cases no radiation-induced liver damage but Gd-BOPTA uptake was seen. Presence of radiation-induced liver damage and absence of Gd-BOPTA uptake was correlated with a former high-dose exposition.ConclusionsAbsence of hepatobiliary MRI contrast media uptake in radiation-exposed liver parenchyma may indicate radiation-induced liver damage. Confirmatory studies are warranted.

  9. Correlative nanoscale imaging of actin filaments and their complexes.

    Science.gov (United States)

    Sharma, Shivani; Zhu, Huanqi; Grintsevich, Elena E; Reisler, Emil; Gimzewski, James K

    2013-07-01

    Actin remodeling is an area of interest in biology in which correlative microscopy can bring a new way to analyze protein complexes at the nanoscale. Advances in EM, X-ray diffraction, fluorescence, and single molecule techniques have provided a wealth of information about the modulation of the F-actin structure and its regulation by actin binding proteins (ABPs). Yet, there are technological limitations of these approaches to achieving quantitative molecular level information on the structural and biophysical changes resulting from ABPs interaction with F-actin. Fundamental questions about the actin structure and dynamics and how these determine the function of ABPs remain unanswered. Specifically, how local and long-range structural and conformational changes result in ABPs induced remodeling of F-actin needs to be addressed at the single filament level. Advanced, sensitive and accurate experimental tools for detailed understanding of ABP-actin interactions are much needed. This article discusses the current understanding of nanoscale structural and mechanical modulation of F-actin by ABPs at the single filament level using several correlative microscopic techniques, focusing mainly on results obtained by Atomic Force Microscopy (AFM) analysis of ABP-actin complexes.

  10. Diagnosing cysts with correlation coefficient images from 2-dimensional freehand elastography.

    Science.gov (United States)

    Booi, Rebecca C; Carson, Paul L; O'Donnell, Matthew; Richards, Michael S; Rubin, Jonathan M

    2007-09-01

    We compared the diagnostic potential of using correlation coefficient images versus elastograms from 2-dimensional (2D) freehand elastography to characterize breast cysts. In this preliminary study, which was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act, we imaged 4 consecutive human subjects (4 cysts, 1 biopsy-verified benign breast parenchyma) with freehand 2D elastography. Data were processed offline with conventional 2D phase-sensitive speckle-tracking algorithms. The correlation coefficient in the cyst and surrounding tissue was calculated, and appearances of the cysts in the correlation coefficient images and elastograms were compared. The correlation coefficient in the cysts was considerably lower (14%-37%) than in the surrounding tissue because of the lack of sufficient speckle in the cysts, as well as the prominence of random noise, reverberations, and clutter, which decorrelated quickly. Thus, the cysts were visible in all correlation coefficient images. In contrast, the elastograms associated with these cysts each had different elastographic patterns. The solid mass in this study did not have the same high decorrelation rate as the cysts, having a correlation coefficient only 2.1% lower than that of surrounding tissue. Correlation coefficient images may produce a more direct, reliable, and consistent method for characterizing cysts than elastograms.

  11. Application of strong zerotrees to compression of correlated MRI image sets

    Science.gov (United States)

    Soloveyko, Olexandr M.; Musatenko, Yurij S.; Kurashov, Vitalij N.; Dubikovskiy, Vladislav A.

    2001-08-01

    It is known that gainful interframe compression of magnetic resonance(MR) image set is quite difficult problem. Only few authors reported gain in performance of compressors like that comparing to separate compression of every MR image from the set (intraframe compression). Known reasons of such a situation are significant noise in MR images and presence of only low frequency correlations in images of the set. Recently we suggested new method of correlated image set compression based on Karhunen-Loeve(KL) transform and special EZW compression scheme with strong zerotrees(KLSEZW). KLSEZW algorithm showed good results in compression of video sequences with low and middle motion even without motion compensation. The paper presents successful application of the basic method and its modification to interframe MR image compression problem.

  12. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    CERN Document Server

    Thyagarajan, Nithyanandan; Bowman, Judd D; Morales, Miguel F

    2015-01-01

    Modern radio telescopes are favoring densely packed array layouts consisting of large numbers of antennas ($N_\\textrm{a}\\gtrsim 1000$). Since the complexity of traditional correlators scales as $\\mathcal{O}(N_\\textrm{a}^2)$, there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (EPIC), we present the first software demonstration of a generalized direct imaging algorithm known as the Modular Optimal Frequency Fourier (MOFF) imager. It takes advantage of the multiplication-convolution theorem of Fourier transforms. Not only does it bring down the cost for dense layouts to $\\mathcal{O}(N_\\textrm{a}\\log_2 N_\\textrm{a})$ but can also image from irregularly arranged heterogeneous antenna arrays. EPIC is highly modular and parallelizable, implemented in object oriented Python, and publicly available. We have verified the images produced to be equivalent to those produced using traditional techniques. We...

  13. Stroke prognosis by applying double thresholds on CT-perfusion-brain images

    Science.gov (United States)

    Chokchaitam, Somchart; Santipromwong, Nittaya; Muengtaweepongsa, Sombat

    2013-03-01

    The CT-perfusion image shows information of brain abnormalities such as its size and location. Generally, neurologist diagnoses stroke disease using CT-perfusion images such as Cerebral blood flow (CBF), cerebral blood volume (CBV). In our previous report, we applied threshold technique to divide amount of CBV and CBF into low and high level. Then, their levels are applied to identify normal tissue areas, dead tissue areas (infract core) and blood-cot tissue areas (infract penumbra). However, it's not totally correct, if the same threshold is applied to the whole area (it must depend on size of blood vessel in that area. In this report, we propose double thresholds to divided CBV and CBF into 3 levels: very low, medium and very high levels. Very low and very high levels are definitely implied to bad areas and good areas, respectively. The proposed double thresholds makes stroke prognosis more accurate. The simulation results confirm that our proposed results closed to results defined from neurologist comparing to the conventional results.

  14. Personality and individual difference correlates of positive body image.

    Science.gov (United States)

    Swami, Viren; Hadji-Michael, Maria; Furnham, Adrian

    2008-09-01

    In the present study, 101 women and 106 men from a community sample of British adults completed the Body Appreciation Scale (BAS), along with a battery of individual difference measures and demographics. Contrary to previous findings, there were no sex differences in BAS scores, either before or after controlling for individual differences in other measures. The results also showed that, moderating for participants' sex, self-assessed attractiveness, educational qualifications, neuroticism, extraversion, and BMI were all significant predictors of body appreciation. In addition, higher media consumption and higher (male-stereotypic) instrumentality were associated with, but did not predict, higher body appreciation. These results are discussed in relation to the extant work on body image.

  15. Fatigue Crack Closure Analysis Using Digital Image Correlation

    Science.gov (United States)

    Leser, William P.; Newman, John A.; Johnston, William M.

    2010-01-01

    Fatigue crack closure during crack growth testing is analyzed in order to evaluate the critieria of ASTM Standard E647 for measurement of fatigue crack growth rates. Of specific concern is remote closure, which occurs away from the crack tip and is a product of the load history during crack-driving-force-reduction fatigue crack growth testing. Crack closure behavior is characterized using relative displacements determined from a series of high-magnification digital images acquired as the crack is loaded. Changes in the relative displacements of features on opposite sides of the crack are used to generate crack closure data as a function of crack wake position. For the results presented in this paper, remote closure did not affect fatigue crack growth rate measurements when ASTM Standard E647 was strictly followed and only became a problem when testing parameters (e.g., load shed rate, initial crack driving force, etc.) greatly exceeded the guidelines of the accepted standard.

  16. Random matrix theory applied to acoustic backscattering and imaging in complex media.

    Science.gov (United States)

    Aubry, Alexandre; Derode, Arnaud

    2009-02-27

    The singular values distribution of the propagation operator in a random medium is investigated in a backscattering configuration. Experiments are carried out with pulsed ultrasonic waves around 3 MHz, using an array of transducers. Coherent backscattering and field correlations are taken into account. Interestingly, the distribution of singular values shows a dramatically different behavior in the single and multiple-scattering regimes. Based on a matrix separation of single and multiple-scattered waves, an experimental illustration of imaging through a highly scattering slab is presented.

  17. Super-resolution image reconstruction methods applied to GFE-referenced navigation system

    Science.gov (United States)

    Yan, Lei; Lin, Yi; Tong, Qingxi

    2007-11-01

    The problem about reference grid data's overlarge spacing, which makes deviated estimation of un-surveyed points and poor accuracy of correlation positioning, has been embarrassing Geophysical Fields of the Earth (GFE) referenced navigation research. The super-resolution images reconstruction methods in remote sensing field give some inspiration, and its brief method, Maximum A-Posterior (MAP) based on Bayesian theory, is transplanted on grid data. The proposed algorithm named MAP-G can implement interpolation of reference data field by reflecting whole distribution trend. Comparison with traditional interpolation algorithms and simulation experiments on underwater terrain/gravity-aided navigation platform, indicate that MAP-G algorithm can effectively improve navigation's performance.

  18. Forward-backward generalized sidelobe canceler beamforming applied to medical ultrasound imaging

    Science.gov (United States)

    Li, Jiake; Chen, Xiaodong; Wang, Yi; Chen, Xiaoshuai; Yu, Daoyin

    2017-01-01

    For adaptive ultrasound imaging, accurate estimation of the covariance matrix is of great importance, and it has a fundamental influence on the performance of the adaptive beamformer. In this paper, a new forward-backward generalized sidelobe canceler (FBGSC) approach is proposed for medical ultrasound imaging, which uses forward and backward subaperture averaging to accurate estimate the covariance matrix. And resulted from accurate estimating of covariance matrix, FBGSC can achieve better lateral resolution and contrast without preprocessing algorithms. Field II is applied to obtain the simulated echo data of scattering points and a circular cyst. Beamforming responses of scattering points show that FBGSC can improve the lateral resolution by 55.7% and 66.6% compared with synthetic aperture (SA) and delay-and-sum (DS), respectively. Similarly, the simulated results of circular cyst show that FBGSC can obtain better beamforming responses than traditional adaptive beamformers. Finally, an experiment is conducted based on the real echo data of a medical ultrasound system. Results demonstrate that the FBGSC can improve the imaging quality of medical ultrasound imaging system, with lower computational demand and higher reliability.

  19. An effective correlated mean-field theory applied in the spin-1/2 Ising ferromagnetic model

    Energy Technology Data Exchange (ETDEWEB)

    Roberto Viana, J.; Salmon, Octávio R. [Universidade Federal do Amazonas – UFAM, Manaus 69077-000, AM (Brazil); Ricardo de Sousa, J. [Universidade Federal do Amazonas – UFAM, Manaus 69077-000, AM (Brazil); National Institute of Science and Technology for Complex Systems, Universidade Federal do Amazonas, 3000, Japiim, 69077-000 Manaus, AM (Brazil); Neto, Minos A.; Padilha, Igor T. [Universidade Federal do Amazonas – UFAM, Manaus 69077-000, AM (Brazil)

    2014-11-15

    We developed a new treatment for mean-field theory applied in spins systems, denominated effective correlated mean-field (ECMF). We apply this theory to study the spin-1/2 Ising ferromagnetic model with nearest-neighbor interactions on a square lattice. We use clusters of finite sizes and study the criticality of the ferromagnetic system, where we obtain a convergence of critical temperature for the value k{sub B}T{sub c}/J≃2.27905±0.00141. Also the behavior of magnetic and thermodynamic properties, using the condition of minimum energy of the physical system is obtained. - Highlights: • We developed spin models to study real magnetic systems. • We study the thermodynamic and magnetic properties of the ferromagnetism. • We enhanced a mean-field theory applied in spins models.

  20. Fractal Analysis of Laplacian Pyramidal Filters Applied to Segmentation of Soil Images

    Directory of Open Access Journals (Sweden)

    J. de Castro

    2014-01-01

    Full Text Available The laplacian pyramid is a well-known technique for image processing in which local operators of many scales, but identical shape, serve as the basis functions. The required properties to the pyramidal filter produce a family of filters, which is unipara metrical in the case of the classical problem, when the length of the filter is 5. We pay attention to gaussian and fractal behaviour of these basis functions (or filters, and we determine the gaussian and fractal ranges in the case of single parameter a. These fractal filters loose less energy in every step of the laplacian pyramid, and we apply this property to get threshold values for segmenting soil images, and then evaluate their porosity. Also, we evaluate our results by comparing them with the Otsu algorithm threshold values, and conclude that our algorithm produce reliable test results.

  1. ZnSe-material phase mask applied to athermalization of infrared imaging systems.

    Science.gov (United States)

    Feng, Bin; Shi, Zelin; Xu, Baoshu; Zhang, Chengshuo; Zhang, Xiaodong

    2016-07-20

    This paper reports a ZnSe-material phase mask that is applied to athermalization of a conventional infrared imaging system. Its principle, design, manufacture, measurement, and performance validation are successively discussed. This paper concludes that a ZnSe-material phase mask has a permissible manufacturing error 2.14 times as large as a Ge-material phase mask. By constructing and solving an optimization problem, the ZnSe-material phase mask is optimally designed. The optimal phase mask is manufactured and measured with a form manufacturing error of 1.370 μm and a surface roughness value of 9.926 nm. Experiments prove that the wavefront coding athermalized longwave infrared (LWIR) imaging system works well over the temperature range from -40°C to +60°C.

  2. Joint Applied Optics and Chinese Optics Letters Feature Introduction: Digital Holography and 3D Imaging

    Institute of Scientific and Technical Information of China (English)

    Ting-Chung Poon; Changhe Zhou; Toyohiko Yatagai; Byoungho Lee; Hongchen Zhai

    2011-01-01

    This feature issue is the fifth installment on digital holography since its inception four years ago.The last four issues have been published after the conclusion of each Topical Meeting "Digital Holography and 3D imaging (DH)." However,this feature issue includes a new key feature-Joint Applied Optics and Chinese Optics Letters Feature Issue.The DH Topical Meeting is the world's premier forum for disseminating the science and technology geared towards digital holography and 3D information processing.Since the meeting's inception in 2007,it has steadily and healthily grown to 130 presentations this year,held in Tokyo,Japan,May 2011.

  3. Lean Six Sigma applied to a process innovation in a mexican health institute's imaging department.

    Science.gov (United States)

    Garcia-Porres, J; Ortiz-Posadas, M R; Pimentel-Aguilar, A B

    2008-01-01

    Delivery of services to a patient has to be given with an acceptable measure of quality that can be monitored through the patient's satisfaction. The objective of this work was to innovate processes eliminating waste and non value-added work in processes done at the Imaging Department in the National Institute of Respiratory Diseases (INER for its Spanish acronym) in Mexico City, to decrease the time a patient spends in a study and increase satisfaction. This innovation will be done using Lean Six Sigma tools and applied in a pilot program.

  4. AN IMPROVED CROSS-CORRELATION METHOD FOR (DIGITAL) PARTICLE IMAGE VELOCIMETRY

    Institute of Scientific and Technical Information of China (English)

    翁文国; 范维澄; 廖光煊; 秦俊

    2001-01-01

    An improved method that brings enhancement in accuracy for the interrogation of (digital) PIV images is described in this paper. This method is based on cross-correlation with discrete window offset, which makes use of a translation of the second interrogation window and rebuilds it considering rotation and shear.The displacement extracted from PIV images is predicted and corrected by means of an iterative procedure. In addition, the displacement vectors are validated at each intermediate of the iteration process. The present improved cross-correlation method is compared with the conventional one in accuracy by interrogation of synthetic and real (digital) PIV images and the interrogation results are discussed.

  5. Contextual filtering method applied to sub-bands of interferometric image decomposition

    Science.gov (United States)

    Belhadj-Aissa, S.; Hocine, F.; Boughacha, M. S.; Belhadj-Aissa, M.

    2016-10-01

    The precision and accuracy of Digital elevation model and deformation measurement, from SAR interferometry (InSAR/DInSAR) depend mainly on the quality of the interferogram. However, the phase noise, which is mainly due to decorrelation between the images and the speckle, makes the step of phase unwrapping most delicate. In this paper, we propose a filtering method that combines the techniques of decomposition into sub-bands and nonlinear local weights. The Spectral / Contextual filter that we propose, inspired from to Goldstein filter is applied to the sub-bands from the wavelet decomposition. To validate the results, we applied to interferometric products tandem pair ERS1/ERS2 taken in the region of Algiers Algeria.

  6. Metabolic brain imaging correlated with clinical features of brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Alavi, J.; Alavi, A.; Dann, R.; Kushner, M.; Chawluk, J.; Powlis, W.; Reivich, M.

    1985-05-01

    Nineteen adults with brain tumors have been studied with positron emission tomography utilizing FDG. Fourteen had biopsy proven cerebral malignant glioma, one each had meningioma, hemangiopericytoma, primitive neuroectodermal tumor (PNET), two had unbiopsied lesions, and one patient had an area of biopsy proven radiation necrosis. Three different patterns of glucose metabolism are observed: marked increase in metabolism at the site of the known tumor in (10 high grade gliomas and the PNET), lower than normal metabolism at the tumor (in 1 grade II glioma, 3 grade III gliomas, 2 unbiopsied low density nonenhancing lesions, and the meningioma), no abnormality (1 enhancing glioma, the hemangiopericytoma and the radiation necrosis.) The metabolic rate of the tumor or the surrounding brain did not appear to be correlated with the history of previous irradiation or chemotherapy. Decreased metabolism was frequently observed in the rest of the affected hemisphere and in the contralateral cerebellum. Tumors of high grade or with enhancing CT characteristics were more likely to show increased metabolism. Among the patients with proven gliomas, survival after PETT scan tended to be longer for those with low metabolic activity tumors than for those with highly active tumors. The authors conclude that PETT may help to predict the malignant potential of tumors, and may add useful clinical information to the CT scan.

  7. Weighted correlation network analysis (WGCNA applied to the tomato fruit metabolome.

    Directory of Open Access Journals (Sweden)

    Matthew V DiLeo

    Full Text Available BACKGROUND: Advances in "omics" technologies have revolutionized the collection of biological data. A matching revolution in our understanding of biological systems, however, will only be realized when similar advances are made in informatic analysis of the resulting "big data." Here, we compare the capabilities of three conventional and novel statistical approaches to summarize and decipher the tomato metabolome. METHODOLOGY: Principal component analysis (PCA, batch learning self-organizing maps (BL-SOM and weighted gene co-expression network analysis (WGCNA were applied to a multivariate NMR dataset collected from developmentally staged tomato fruits belonging to several genotypes. While PCA and BL-SOM are appropriate and commonly used methods, WGCNA holds several advantages in the analysis of highly multivariate, complex data. CONCLUSIONS: PCA separated the two major genetic backgrounds (AC and NC, but provided little further information. Both BL-SOM and WGCNA clustered metabolites by expression, but WGCNA additionally defined "modules" of co-expressed metabolites explicitly and provided additional network statistics that described the systems properties of the tomato metabolic network. Our first application of WGCNA to tomato metabolomics data identified three major modules of metabolites that were associated with ripening-related traits and genetic background.

  8. Measure of Information Content of Remotely Sensed Images Accounting for Spatial Correlation

    Directory of Open Access Journals (Sweden)

    ZHANG Ying

    2015-10-01

    Full Text Available A measure is proposed based on the information theory and geostatistics to evaluate information content in remotely sensed images. The method is based on the additive noise model and maximum mutual information.These factors affecting the information content have been taken into account, such as noise, spatial correlation and so on. It is suitable for measuring the information content in optical images that have robust spatial correlation with different land cover types. An experiment was performed on a Landsat TM image with three different kinds of land cover types (city, farmland and mountain. The result shows that city has the most information content. It also proves that there is a log positive correlation between information content and the variance of the images.

  9. Correlation of the same fields imaged in the TEM, confocal, LM, and microCT by image registration: from specimen preparation to displaying a final composite image.

    Science.gov (United States)

    Keene, Douglas R; Tufa, Sara F; Wong, Melissa H; Smith, Nicholas R; Sakai, Lynn Y; Horton, William A

    2014-01-01

    Correlated imaging is the process of imaging a specimen with two complementary modalities and then registering and overlaying the fields obtained in each modality to create a composite view. One of the images is made somewhat transparent, allowing detail in the underlying image to be visible and assisting in the registration of the two images. As an example, an image localizing a specific tissue component by fluorescence may be overlaid atop a TEM image of the same field. The resulting composite image would demonstrate specific ultrastructural features in the high-resolution TEM field, which are colorized in the overlay. Other examples include composites from MicroCT or soft X-ray images overlaid atop light microscopy or TEM images. Automated image registration may be facilitated by a variety of sophisticated computer programs utilized by high-throughput laboratories. This chapter is meant for the more occasional user wishing to align images manually. ImageJ is a public domain, image processing program developed at the National Institutes of Health and is available to anyone as a free download. ImageJ performs marvelously well for the purpose of image registration; therefore, step-by-step instructions are included here. Specimen handling, including fixation and choice of embedding media, is not straightforward for correlative imaging. A step-by-step description of the protocols which work in our laboratory is included for simultaneous localization in LM, EM and micro-CT, as well as maintaining GFP emission in tissue embedded for TEM. © 2014 Elsevier Inc. All rights reserved.

  10. Effects of reusing baseline volumes of interest by applying (non-rigid image registration on positron emission tomography response assessments.

    Directory of Open Access Journals (Sweden)

    Floris H P van Velden

    Full Text Available OBJECTIVES: Reusing baseline volumes of interest (VOI by applying non-rigid and to some extent (local rigid image registration showed good test-retest variability similar to delineating VOI on both scans individually. The aim of the present study was to compare response assessments and classifications based on various types of image registration with those based on (semi-automatic tumour delineation. METHODS: Baseline (n = 13, early (n = 12 and late (n = 9 response (after one and three cycles of treatment, respectively whole body [(18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (PET/CT scans were acquired in subjects with advanced gastrointestinal malignancies. Lesions were identified for early and late response scans. VOI were drawn independently on all scans using an adaptive 50% threshold method (A50. In addition, various types of (non-rigid image registration were applied to PET and/or CT images, after which baseline VOI were projected onto response scans. Response was classified using PET Response Criteria in Solid Tumors for maximum standardized uptake value (SUV(max, average SUV (SUV(mean, peak SUV (SUV(peak, metabolically active tumour volume (MATV, total lesion glycolysis (TLG and the area under a cumulative SUV-volume histogram curve (AUC. RESULTS: Non-rigid PET-based registration and non-rigid CT-based registration followed by non-rigid PET-based registration (CTPET did not show differences in response classifications compared to A50 for SUV(max and SUV(peak, however, differences were observed for MATV, SUV(mean, TLG and AUC. For the latter, these registrations demonstrated a poorer performance for small lung lesions (<2.8 ml, whereas A50 showed a poorer performance when another area with high uptake was close to the target lesion. All methods were affected by lesions with very heterogeneous tracer uptake. CONCLUSIONS: Non-rigid PET- and CTPET-based image registrations may be used to classify response

  11. Correlated image set compression system based on new fast efficient algorithm of Karhunen-Loeve transform

    Science.gov (United States)

    Musatenko, Yurij S.; Kurashov, Vitalij N.

    1998-10-01

    The paper presents improved version of our new method for compression of correlated image sets Optimal Image Coding using Karhunen-Loeve transform (OICKL). It is known that Karhunen-Loeve (KL) transform is most optimal representation for such a purpose. The approach is based on fact that every KL basis function gives maximum possible average contribution in every image and this contribution decreases most quickly among all possible bases. So, we lossy compress every KL basis function by Embedded Zerotree Wavelet (EZW) coding with essentially different loss that depends on the functions' contribution in the images. The paper presents new fast low memory consuming algorithm of KL basis construction for compression of correlated image ensembles that enable our OICKL system to work on common hardware. We also present procedure for determining of optimal losses of KL basic functions caused by compression. It uses modified EZW coder which produce whole PSNR (bitrate) curve during the only compression pass.

  12. Correlation-based virtual source imaging in strongly scattering random media

    Science.gov (United States)

    Garnier, Josselin; Papanicolaou, George

    2012-07-01

    Array imaging in a strongly scattering medium is limited because coherent signals recorded at the array and coming from a reflector to be imaged are weak and dominated by incoherent signals coming from multiple scattering by the medium. If, however, an auxiliary passive array can be placed between the reflector to be imaged and the scattering medium then the cross correlations of the incoherent signals on this array can also be used to image the reflector. In this paper, we show both in the weakly scattering paraxial regime and in strongly scattering layered media that this cross-correlation approach produces images as if the medium between the sources and the passive array was homogeneous and the auxiliary passive array was an active one made up of both sources and receivers.

  13. Pulmonary involvement in Kaposi sarcoma: correlation between imaging and pathology.

    Science.gov (United States)

    Gasparetto, Taisa Davaus; Marchiori, Edson; Lourenço, Sílvia; Zanetti, Gláucia; Vianna, Alberto Domingues; Santos, Alair A S M D; Nobre, Luiz Felipe

    2009-07-14

    Kaposi sarcoma is a low-grade mesenchymal tumor involving blood and lymphatic vessels. There are four variants of this disease, each presenting a different clinical manifestation: classic or sporadic, African or endemic, organ transplant-related or iatrogenic, and AIDS-related or epidemic. Kaposi sarcoma is the most common tumor among patients with HIV infection, occurring predominantly in homosexual or bisexual men. The pulmonary involvement in Kaposi sarcoma occurs commonly in critically immunosupressed patients who commonly have had preceding mucocutaneous or digestive involvement.The etiology of Kaposi sarcoma is not precisely established; genetic, hormonal, and immune factors, as well as infectious agents, have all been implicated. There is evidence from epidemiologic, serologic, and molecular studies that Kaposi sarcoma is associated with human herpes virus type 8 infection. The disease starts as a reactive polyclonal angioproliferative response towards this virus, in which polyclonal cells change to form oligoclonal cell populations that expand and undergo malignant transformation.The diagnosis of pulmonary involvement in Kaposi sarcoma usually can be made by a combination of clinical, radiographic, and laboratory findings, together with the results of bronchoscopy and transbronchial biopsy. Chest high-resolution computed tomography scans commonly reveal peribronchovascular and interlobular septal thickening, bilateral and symmetric ill-defined nodules in a peribronchovascular distribution, fissural nodularity, mediastinal adenopathies, and pleural effusions. Correlation between the high-resolution computed tomography findings and the pathology revealed by histopathological analysis demonstrate that the areas of central peribronchovascular infiltration represent tumor growth involving the bronchovascular bundles, with nodules corresponding to proliferations of neoplastic cells into the pulmonary parenchyma. The interlobular septal thickening may represent

  14. Pulmonary involvement in Kaposi sarcoma: correlation between imaging and pathology

    Directory of Open Access Journals (Sweden)

    Vianna Alberto

    2009-07-01

    Full Text Available Abstract Kaposi sarcoma is a low-grade mesenchymal tumor involving blood and lymphatic vessels. There are four variants of this disease, each presenting a different clinical manifestation: classic or sporadic, African or endemic, organ transplant-related or iatrogenic, and AIDS-related or epidemic. Kaposi sarcoma is the most common tumor among patients with HIV infection, occurring predominantly in homosexual or bisexual men. The pulmonary involvement in Kaposi sarcoma occurs commonly in critically immunosupressed patients who commonly have had preceding mucocutaneous or digestive involvement. The etiology of Kaposi sarcoma is not precisely established; genetic, hormonal, and immune factors, as well as infectious agents, have all been implicated. There is evidence from epidemiologic, serologic, and molecular studies that Kaposi sarcoma is associated with human herpes virus type 8 infection. The disease starts as a reactive polyclonal angioproliferative response towards this virus, in which polyclonal cells change to form oligoclonal cell populations that expand and undergo malignant transformation. The diagnosis of pulmonary involvement in Kaposi sarcoma usually can be made by a combination of clinical, radiographic, and laboratory findings, together with the results of bronchoscopy and transbronchial biopsy. Chest high-resolution computed tomography scans commonly reveal peribronchovascular and interlobular septal thickening, bilateral and symmetric ill-defined nodules in a peribronchovascular distribution, fissural nodularity, mediastinal adenopathies, and pleural effusions. Correlation between the high-resolution computed tomography findings and the pathology revealed by histopathological analysis demonstrate that the areas of central peribronchovascular infiltration represent tumor growth involving the bronchovascular bundles, with nodules corresponding to proliferations of neoplastic cells into the pulmonary parenchyma. The interlobular

  15. Industrial defect discrimination applying infrared imaging spectroscopy and artificial neural networks

    Science.gov (United States)

    Garcia-Allende, Pilar Beatriz; Conde, Olga M.; Madruga, Francisco J.; Cubillas, Ana M.; Lopez-Higuera, Jose M.

    2008-03-01

    A non-intrusive infrared sensor for the detection of spurious elements in an industrial raw material chain has been developed. The system is an extension to the whole near infrared range of the spectrum of a previously designed system based on the Vis-NIR range (400 - 1000 nm). It incorporates a hyperspectral imaging spectrograph able to register simultaneously the NIR reflected spectrum of the material under study along all the points of an image line. The working material has been different tobacco leaf blends mixed with typical spurious elements of this field such as plastics, cardboards, etc. Spurious elements are discriminated automatically by an artificial neural network able to perform the classification with a high degree of accuracy. Due to the high amount of information involved in the process, Principal Component Analysis is first applied to perform data redundancy removal. By means of the extension to the whole NIR range of the spectrum, from 1000 to 2400 nm, the characterization of the material under test is highly improved. The developed technique could be applied to the classification and discrimination of other materials, and, as a consequence of its non-contact operation it is particularly suitable for food quality control.

  16. Correlating hemodynamic magnetic resonance imaging with high-field intracranial vessel wall imaging in stroke.

    Science.gov (United States)

    Langdon, Weston; Donahue, Manus J; van der Kolk, Anja G; Rane, Swati; Strother, Megan K

    2014-06-01

    Vessel wall magnetic resonance imaging at ultra-high field (7 Tesla) can be used to visualize vascular lesions noninvasively and holds potential for improving stroke-risk assessment in patients with ischemic cerebrovascular disease. We present the first multi-modal comparison of such high-field vessel wall imaging with more conventional (i) 3 Tesla hemodynamic magnetic resonance imaging and (ii) digital subtraction angiography in a 69-year-old male with a left temporal ischemic infarct.

  17. Neural correlates of monocular and binocular depth cues based on natural images: a LORETA analysis.

    Science.gov (United States)

    Fischmeister, Florian Ph S; Bauer, Herbert

    2006-10-01

    Functional imaging studies investigating perception of depth rely solely on one type of depth cue based on non-natural stimulus material. To overcome these limitations and to provide a more realistic and complete set of depth cues natural stereoscopic images were used in this study. Using slow cortical potentials and source localization we aimed to identify the neural correlates of monocular and binocular depth cues. This study confirms and extends functional imaging studies, showing that natural images provide a good, reliable, and more realistic alternative to artificial stimuli, and demonstrates the possibility to separate the processing of different depth cues.

  18. Applying GA for Optimizing the User Query in Image and Video Retrieval

    Directory of Open Access Journals (Sweden)

    Ehsan Lotfi

    2014-12-01

    Full Text Available In an information retrieval system, the query can be made by user sketch. The new method presented here, optimizes the user sketch and applies the optimized query to retrieval the information. This optimization may be used in Content-Based Image Retrieval (CBIR and Content-Based Video Retrieval (CBVR which is based on trajectory extraction. To optimize the retrieval process, one stage of retrieval is performed by the user sketch. The retrieval criterion is based on the proposed distance metric from the user query. Retrieved answers are considered as the primary population for evolutionary optimization. The optimized query may be achieved through reproducing and minimizing the proposed measurement by using Genetic algorithm (GA. The optimized query could then be used for the retrieval of concepts from a given Data Base (DB. The proposed algorithms are evaluated for trajectory retrieval from urban traffic surveillance video and image retrieval from a DB. Practical implementations have demonstrated the high efficiency of this system in trajectory retrieval and image indexing.

  19. Digital Image Analysis of Ultrasound B-mode images of Carotid Atherosclerotic Plaque: Correlation with Histological Examination

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Rosendal, Kim; Grønholdt, Marie-Louise Moes

    1996-01-01

    This paper reports on a study of how well texture features extracted from B-mode images of atherosclerotic plaque correlates with histological results obtained from the same plaque after carotid endarterectomy. The study reveals that a few second order texture features (diagonal moment, standard...

  20. Single-step scanner-based digital image correlation (SB-DIC) method for large deformation mapping in rubber

    Science.gov (United States)

    Goh, C. P.; Ismail, H.; Yen, K. S.; Ratnam, M. M.

    2017-01-01

    The incremental digital image correlation (DIC) method has been applied in the past to determine strain in large deformation materials like rubber. This method is, however, prone to cumulative errors since the total displacement is determined by combining the displacements in numerous stages of the deformation. In this work, a method of mapping large strains in rubber using DIC in a single-step without the need for a series of deformation images is proposed. The reference subsets were deformed using deformation factors obtained from the fitted mean stress-axial stretch ratio curve obtained experimentally and the theoretical Poisson function. The deformed reference subsets were then correlated with the deformed image after loading. The recently developed scanner-based digital image correlation (SB-DIC) method was applied on dumbbell rubber specimens to obtain the in-plane displacement fields up to 350% axial strain. Comparison of the mean axial strains determined from the single-step SB-DIC method with those from the incremental SB-DIC method showed an average difference of 4.7%. Two rectangular rubber specimens containing circular and square holes were deformed and analysed using the proposed method. The resultant strain maps from the single-step SB-DIC method were compared with the results of finite element modeling (FEM). The comparison shows that the proposed single-step SB-DIC method can be used to map the strain distribution accurately in large deformation materials like rubber at much shorter time compared to the incremental DIC method.

  1. Two-dimensional confocal laser scanning microscopy image correlation for nanoparticle flow velocimetry

    Science.gov (United States)

    Jun, Brian; Giarra, Matthew; Golz, Brian; Main, Russell; Vlachos, Pavlos

    2016-11-01

    We present a methodology to mitigate the major sources of error associated with two-dimensional confocal laser scanning microscopy (CLSM) images of nanoparticles flowing through a microfluidic channel. The correlation-based velocity measurements from CLSM images are subject to random error due to the Brownian motion of nanometer-sized tracer particles, and a bias error due to the formation of images by raster scanning. Here, we develop a novel ensemble phase correlation with dynamic optimal filter that maximizes the correlation strength, which diminishes the random error. In addition, we introduce an analytical model of CLSM measurement bias error correction due to two-dimensional image scanning of tracer particles. We tested our technique using both synthetic and experimental images of nanoparticles flowing through a microfluidic channel. We observed that our technique reduced the error by up to a factor of ten compared to ensemble standard cross correlation (SCC) for the images tested in the present work. Subsequently, we will assess our framework further, by interrogating nanoscale flow in the cell culture environment (transport within the lacunar-canalicular system) to demonstrate our ability to accurately resolve flow measurements in a biological system.

  2. High-accuracy and robust face recognition system based on optical parallel correlator using a temporal image sequence

    Science.gov (United States)

    Watanabe, Eriko; Ishikawa, Mami; Ohta, Maiko; Kodate, Kashiko

    2005-09-01

    Face recognition is used in a wide range of security systems, such as monitoring credit card use, searching for individuals with street cameras via Internet and maintaining immigration control. There are still many technical subjects under study. For instance, the number of images that can be stored is limited under the current system, and the rate of recognition must be improved to account for photo shots taken at different angles under various conditions. We implemented a fully automatic Fast Face Recognition Optical Correlator (FARCO) system by using a 1000 frame/s optical parallel correlator designed and assembled by us. Operational speed for the 1: N (i.e. matching a pair of images among N, where N refers to the number of images in the database) identification experiment (4000 face images) amounts to less than 1.5 seconds, including the pre/post processing. From trial 1: N identification experiments using FARCO, we acquired low error rates of 2.6% False Reject Rate and 1.3% False Accept Rate. By making the most of the high-speed data-processing capability of this system, much more robustness can be achieved for various recognition conditions when large-category data are registered for a single person. We propose a face recognition algorithm for the FARCO while employing a temporal image sequence of moving images. Applying this algorithm to a natural posture, a two times higher recognition rate scored compared with our conventional system. The system has high potential for future use in a variety of purposes such as search for criminal suspects by use of street and airport video cameras, registration of babies at hospitals or handling of an immeasurable number of images in a database.

  3. Intrasubject correlation between static scan and distribution volume images for [{sup 11}C]flumazenil PET

    Energy Technology Data Exchange (ETDEWEB)

    Mishina, Masahiro [Nippon Medical School, Tokyo (Japan); Senda, Michio; Kimura, Yuichi [and others

    2000-06-01

    Accumulation of [{sup 11}C]flumazenil (FMZ) reflects central nervous system benzodiazepine receptor (BZR). We searched for the optimal time for a static PET scan with FMZ as semi-quantitative imaging of BZR distribution. In 10 normal subjects, a dynamic series of decay-corrected PET scans was performed for 60 minutes, and the arterial blood was sampled during the scan to measure radioactivity and labeled metabolites. We generated 13 kinds of ''static scan'' images from the dynamic scan in each subject, and analyzed the pixel correlation for these images versus distribution volume (DV) images. We also analyzed the time for the [{sup 11}C]FMZ in plasma and tissue to reach the equilibrium. The intra-subject pixel correlation demonstrated that the static scan'' images for the period centering around 30 minutes post-injection had the strongest linear correlation with the DV image. The ratio of radioactivity in the cortex to that in the plasma reached a peak at 40 minutes after injection. Considering the physical decay and patient burden, we conclude that the decay corrected static scan for [{sup 11}C]FMZ PET as semi-quantitative imaging of BZR distribution is to be optimally acquired from 20 to 40 minutes after injection. (author)

  4. Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fonte, Mariana Vieira de Melo da; Otaduy, Maria Concepcion Garcia; Lucato, Leandro Tavares; Reed, Umbertina Conti; Leite, Claudia da Costa [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Inst. de Radiologia]. E-mail: mvmfonte@uol.com.br; Costa, Maria Olivia Rodrigues; Amaral, Raquel Portugal Guimaraes [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Radiologia; Reed, Umbertina Conti [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Neurologia; Rosemberg, Sergio [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Dept. de Patologia

    2008-11-15

    To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumors characteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, and diffusion-weighted imaging and spectroscopy findings. In most of cases the tumors were centered in the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T 1-weighted images and intermediate/hyperintense on T 2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquired with STEAM technique (n = 6) demonstrated decreased Na a / Cr ratio (83.3%) and increased Co/Cr (100%) and ml/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. (author)

  5. Dependence of Adaptive Cross-correlation Algorithm Performance on the Extended Scene Image Quality

    Science.gov (United States)

    Sidick, Erkin

    2008-01-01

    Recently, we reported an adaptive cross-correlation (ACC) algorithm to estimate with high accuracy the shift as large as several pixels between two extended-scene sub-images captured by a Shack-Hartmann wavefront sensor. It determines the positions of all extended-scene image cells relative to a reference cell in the same frame using an FFT-based iterative image-shifting algorithm. It works with both point-source spot images as well as extended scene images. We have demonstrated previously based on some measured images that the ACC algorithm can determine image shifts with as high an accuracy as 0.01 pixel for shifts as large 3 pixels, and yield similar results for both point source spot images and extended scene images. The shift estimate accuracy of the ACC algorithm depends on illumination level, background, and scene content in addition to the amount of the shift between two image cells. In this paper we investigate how the performance of the ACC algorithm depends on the quality and the frequency content of extended scene images captured by a Shack-Hatmann camera. We also compare the performance of the ACC algorithm with those of several other approaches, and introduce a failsafe criterion for the ACC algorithm-based extended scene Shack-Hatmann sensors.

  6. Three-dimensional single-particle imaging using angular correlations from X-ray laser data.

    Science.gov (United States)

    Liu, Haiguang; Poon, Billy K; Saldin, Dilano K; Spence, John C H; Zwart, Peter H

    2013-07-01

    Femtosecond X-ray pulses from X-ray free-electron laser sources make it feasible to conduct room-temperature solution scattering experiments far below molecular rotational diffusion timescales. Owing to the ultra-short duration of each snapshot in these fluctuation scattering experiments, the particles are effectively frozen in space during the X-ray exposure. In contrast to standard small-angle scattering experiments, the resulting scattering patterns are anisotropic. The intensity fluctuations observed in the diffraction images can be used to obtain structural information embedded in the average angular correlation of the Fourier transform of the scattering species, of which standard small-angle scattering data are a subset. The additional information contained in the data of these fluctuation scattering experiments can be used to determine the structure of macromolecules in solution without imposing symmetry or spatial restraints during model reconstruction, reducing ambiguities normally observed in solution scattering studies. In this communication, a method that utilizes fluctuation X-ray scattering data to determine low-resolution solution structures is presented. The method is validated with theoretical data calculated from several representative molecules and applied to the reconstruction of nanoparticles from experimental data collected at the Linac Coherent Light Source.

  7. Photon efficiency optimization in time-correlated single photon counting technique for fluorescence lifetime imaging systems.

    Science.gov (United States)

    Turgeman, Lior; Fixler, Dror

    2013-06-01

    In time-correlated single photon counting (TCSPC) systems, the maximum signal throughput is limited by the occurrence of pile-up and other effects. In many biological applications that exhibit high levels of fluorescence intensity (FI), pile-up-related distortions yield serious distortions in the fluorescence lifetime (FLT) calculation as well as significant decrease in the signal-to-noise ratio (SNR). Recent developments that allow the use of high-repetition-rate light sources (in the range of 50-100 MHz) in fluorescence lifetime imaging (FLIM) experiments enable minimization of pile-up-related distortions. However, modern TCSPC configurations that use high-repetition-rate excitation sources for FLIM suffer from dead-time-related distortions that cause unpredictable distortions of the FI signal. In this study, the loss of SNR is described by F- value as it is typically done in FLIM systems. This F-value describes the relation of the relative standard deviation in the estimated FLT to the relative standard deviation in FI measurements. Optimization of the F-value allows minimization of signal distortion, as well as shortening of the acquisition time for certain samples. We applied this method for Fluorescein, Rhodamine B, and Erythrosine fluorescent solutions that have different FLT values (4 ns, 1.67 ns, and 140 ps, respectively).

  8. Stress distribution retrieval in granular materials: A multi-scale model and digital image correlation measurements

    Science.gov (United States)

    Bruno, Luigi; Decuzzi, Paolo; Gentile, Francesco

    2016-01-01

    The promise of nanotechnology lies in the possibility of engineering matter on the nanoscale and creating technological interfaces that, because of their small scales, may directly interact with biological objects, creating new strategies for the treatment of pathologies that are otherwise beyond the reach of conventional medicine. Nanotechnology is inherently a multiscale, multiphenomena challenge. Fundamental understanding and highly accurate predictive methods are critical to successful manufacturing of nanostructured materials, bio/mechanical devices and systems. In biomedical engineering, and in the mechanical analysis of biological tissues, classical continuum approaches are routinely utilized, even if these disregard the discrete nature of tissues, that are an interpenetrating network of a matrix (the extra cellular matrix, ECM) and a generally large but finite number of cells with a size falling in the micrometer range. Here, we introduce a nano-mechanical theory that accounts for the-non continuum nature of bio systems and other discrete systems. This discrete field theory, doublet mechanics (DM), is a technique to model the mechanical behavior of materials over multiple scales, ranging from some millimeters down to few nanometers. In the paper, we use this theory to predict the response of a granular material to an external applied load. Such a representation is extremely attractive in modeling biological tissues which may be considered as a spatial set of a large number of particulate (cells) dispersed in an extracellular matrix. Possibly more important of this, using digital image correlation (DIC) optical methods, we provide an experimental verification of the model.

  9. Robust full-field measurement considering rotation using digital image correlation

    Science.gov (United States)

    Wu, Rong; Qian, Hao; Zhang, Dongsheng

    2016-10-01

    Digital image correlation (DIC) has been widely accepted as a method for displacement and strain measurement and is applied in a variety of engineering fields. Most DIC algorithms encounter errors in measuring the deformation in conditions that involve rotation since they are designed without considering rotation of the deformed object. In this paper, a robust and automated DIC method capable of determining full-field displacement and strain components with random rotations has been presented. The algorithm starts with the determination of the initial position of the seed point in the integer-pixel domain. An approximate rotational angle between the reference and the deformed subset is estimated using an automated feature matching technology. A two-step Newton-Raphson algorithm has been developed for optimizing a suite of variables including displacement, strain and the rotational angle to achieve subpixel accuracy. A reliable propagation scheme, which enables rapid determination of the initial guess for full-field analysis is also proposed. Results from numerical simulations are used to validate the feasibility of the proposed DIC method. An application to 3-point bending with large deflection shows that the algorithm can be employed to measure displacement or strain parameters of the deformed object with arbitrary angles of rotation.

  10. Non-invasive real-time imaging through scattering layers and around corners via speckle correlations

    CERN Document Server

    Katz, Ori; Fink, Mathias; Gigan, Sylvain

    2014-01-01

    Imaging with optical resolution through and inside complex samples is a difficult challenge with important applications in many fields. The fundamental problem is that inhomogeneous samples, such as biological tissues, randomly scatter and diffuse light, impeding conventional image formation. Despite many advancements, no current method enables to noninvasively image in real-time using diffused light. Here, we show that owing to the memory-effect for speckle correlations, a single image of the scattered light, captured with a standard high-resolution camera, encodes all the information that is required to image through the medium or around a corner. We experimentally demonstrate single-shot imaging through scattering media and around corners using incoherent light and various samples, from white paint to dynamic biological samples. Our lensless technique is simple, does not require laser sources, wavefront-shaping, nor time-gated detection, and is realized here using a camera-phone. It has the potential to en...

  11. Noise-assisted correlation algorithm for suppressing noise-induced artifacts in ultrasonic Nakagami images.

    Science.gov (United States)

    Tsui, Po-Hsiang; Yeh, Chih-Kuang; Huang, Chih-Chung

    2012-05-01

    Ultrasonic Nakagami images can complement conventional B-mode images for scatterer characterization. White noise in anechoic areas leads to artifacts that affect the Nakagami image to characterize tissues. Artifact removal requires rejection of the white noise without deforming the backscattered waveform. This study proposes a noise-assisted correlation algorithm (NCA) and carries out simulations, phantom experiments, and clinical measurements to validate its feasibility and practicality. The simulation results show that the NCA can reject white noise in an anechoic area without any deformation of the backscattered waveforms. The results obtained from phantoms and tissues further demonstrate that the proposed NCA can suppress a Nakagami image artifact without changing the texture of the Nakagami image of the scattering background. The NCA is an essential algorithm to construct artifact-free Nakagami image for correctly reflecting scatterer properties of biological tissues.

  12. Compensation of focal plane image motion perturbations with optical correlator in feedback loop

    Science.gov (United States)

    Janschek, Klaus; Tchernykh, Valerij; Dyblenko, Serguei; Flandin, Gregory; Harnisch, Bernd

    2004-11-01

    The paper presents a concept of a smart pushbroom imaging system with compensation of attitude instability effects. The compensation is performed by active opto-mechatronic stabilization of the focal plane image motion in a closed loop system with visual feedback on base of an auxiliary matrix image sensor and an onboard optical correlator. In this way the effects of the attitude instability, vibrations and micro shocks can be neutralized, the image quality improved and the requirements to satellite attitude stability reduced. To prove the feasibility and to estimate the effectiveness of the image motion stabilization, a performance model of the smart imaging system has been developed and a simulation experiment has been carried out. The description of the performance model and the results of the simulation experiment are also given.

  13. Application of digital image correlation to full-field measurement of shrinkage strain of dental composites

    Institute of Scientific and Technical Information of China (English)

    Jian-ying LI; Andrew LAU; Alex S.L.FOK

    2013-01-01

    Objectives:Polymerization shrinkage of dental composites remains a major concern in restorative dentistry because it can lead to micro-cracking of the tooth and debonding at the tooth-restoration interface.The aim of this study was to measure the full-field polymerization shrinkage of dental composites using the optical digital image correlation (DIC) method and to evaluate how the measurement is influenced by the factors in experiment setup and image analysis.Methods:Four commercial dental composites,Premise Dentine,Z100,Z250 and Tetric EvoCeram,were tested.Composite was first placed into a slot mould to form a bar specimen with rectangular-section of 4 mm×2 mm,followed by the surface painting to create irregular speckles.Curing was then applied at one end of the specimen while the other part were covered against curing light for simulating the clinical curing condition of composite in dental cavity.The painted surface was recorded by a charge-coupled device (CCD) camera before and after curing.Subsequently,the volumetric shrinkage of the specimen was calculated with specialist DIC software based on image cross correlation.In addition,a few factors that may influence the measuring accuracy,including the subset window size,speckle size,illumination light and specimen length,were also evaluated.Results:The volumetric shrinkage of the specimen generally decreases with increasing distance from the irradiated surface with a conspicuous exception being the composite Premise Dentine as its maximum shrinkage occurred at a subsurface distance of about 1 mm instead of the irradiated surface.Zl00 had the greatest maximum shrinkage strain,followed by Z250,Tetric EvoCeram and then Premise Dentine.Larger subset window size made the shrinkage strain contour smoother.But the cost was that some details in the heterogeneity of the material were lost.Very small subset window size resulted in a lot of noise in the data,making it difficult to discern the general pattern in the strain

  14. Gastrointestinal stromal tumours: Correlation of modified NIH risk stratification with diffusion-weighted MR imaging as an imaging biomarker

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Tae Wook [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, Seong Hyun, E-mail: kshyun@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Jang, Kyung Mi; Choi, Dongil [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Ha, Sang Yun; Kim, Kyoung-Mee [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kang, Won Ki [Division of Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, Min Ji [Biostatics Unit, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul 135-710 (Korea, Republic of)

    2015-01-15

    Highlights: • Except size and necrosis, conventional MR findings of GISTs were not significantly different according to the modified NIH criteria. • The ADC values of GISTs were negatively correlated with the modified NIH criteria. • The ADC value can be helpful for the determination of intermediate or high-risk GISTs. - Abstract: Purpose: To evaluate the correlation of risk grade of gastrointestinal stromal tumours (GISTs) based on modified National Institutes of Health (NIH) criteria with conventional magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging. Methods: We included 22 patients with histopathologically proven GISTs in the stomach or small bowel who underwent pre-operative gadoxetic acid-enhanced MR imaging and DW imaging. We retrospectively assessed correlations between morphologic findings, qualitative (signal intensity, consensus from two observers) and quantitative (degree of dynamic enhancement using signal intensity of tumour/muscle ratio and apparent diffusion coefficient [ADC]) values, and the modified NIH criteria for risk stratification. Spearman partial correlation analysis was used to control for tumour size as a confounding factor. The optimal cut-off level of ADC values for intermediate or high risk GISTs was analyzed using a receiver operating characteristic analysis. Results: Except tumour size and necrosis, conventional MR imaging findings, including the degree of dynamic enhancement, were not significantly different according to the modified NIH criteria (p > 0.05). Tumour ADC values were negatively correlated with the modified NIH criteria, before and after adjustment of tumour size (ρ = −0.754; p < 0.001 and ρ = −0.513; p = 0.017, respectively). The optimal cut-off value for the determination of intermediate or high-risk GISTs was 1.279 × 10{sup −3} mm{sup 2}/s (100% sensitivity, 69.2% specificity, 81.8% accuracy). Conclusion: Except tumour size and necrosis, conventional MR imaging findings did not

  15. Digital image correlation involves an inverse problem: A regularization scheme based on subset size constraint

    Science.gov (United States)

    Zhan, Qin; Yuan, Yuan; Fan, Xiangtao; Huang, Jianyong; Xiong, Chunyang; Yuan, Fan

    2016-06-01

    Digital image correlation (DIC) is essentially implicated in a class of inverse problem. Here, a regularization scheme is developed for the subset-based DIC technique to effectively inhibit potential ill-posedness that likely arises in actual deformation calculations and hence enhance numerical stability, accuracy and precision of correlation measurement. With the aid of a parameterized two-dimensional Butterworth window, a regularized subpixel registration strategy is established, in which the amount of speckle information introduced to correlation calculations may be weighted through equivalent subset size constraint. The optimal regularization parameter associated with each individual sampling point is determined in a self-adaptive way by numerically investigating the curve of 2-norm condition number of coefficient matrix versus the corresponding equivalent subset size, based on which the regularized solution can eventually be obtained. Numerical results deriving from both synthetic speckle images and actual experimental images demonstrate the feasibility and effectiveness of the set of newly-proposed regularized DIC algorithms.

  16. The feasibility and application of gray scale adjustment method in high temperature digital image correlation

    Science.gov (United States)

    Wang, Shen; Yao, Xue Feng; Su, Yun Quan; Liu, Wei

    2017-02-01

    In this paper, the basic principle and application of linear gray scale adjustment method are investigated in high temperature digital image correlation (DIC) technology. First, the simple linear gray scale adjustment method is proposed, which can adjust the gray scale value of the saturated pixels and diminish the correlation error caused by the saturated pixels. Then, both the simulated high temperature images and DIC correlation results before and after the gray scale adjustment are provided and analyzed to verify its effectiveness, in which the displacement error decreased from 0.1 pixels to 0.04 pixels after the linear gray scale adjustment for high temperature images. Finally, the linear gray scale adjustment method is used to extract the displacement with high accuracy in high temperature experiment of SiC specimen, and the displacement error decreased from 0.5 pixels to 0.1 pixels after the linear gray scale adjustment.

  17. Optical coherence tomography imaging of psoriasis vulgaris: correlation with histology and disease severity

    DEFF Research Database (Denmark)

    Morsy, Hanan; Kamp, Søren; Thrane, Lars;

    2010-01-01

    Epidermal thickness (ET) has been suggested as a surrogate measure of psoriasis severity. Optical coherence tomography (OCT) is a recent imaging technology that provides real-time skin images to a depth of 1.8 mm with a micrometre resolution. OCT may provide an accurate in vivo measure of ET. It is...... with a stronger entrance signal, a serrated dermo-epidermal junction was found and a less signal intensity in the dermis as shown in OCT images. ET measured in untreated plaques was thicker reflecting epidermal hyperproliferation and inflammation. The changes were significantly correlated with the biopsy grading...... (r 2 = 0.41, p = 0.001) and ET significantly decreased with treatment (p = 0.0001). ET correlated significantly with self-reported measures of disease severity, but not with physician-assessed global PASI. The data suggest that OCT may be used to measure ET in psoriasis and the measurements correlate...

  18. Optical Measurement Techniques for Rocket Engine Testing and Component Applications: Digital Image Correlation and Dynamic Photogrammetry

    Science.gov (United States)

    Gradl, Paul

    2016-01-01

    NASA Marshall Space Flight Center (MSFC) has been advancing dynamic optical measurement systems, primarily Digital Image Correlation, for extreme environment rocket engine test applications. The Digital Image Correlation (DIC) technology is used to track local and full field deformations, displacement vectors and local and global strain measurements. This technology has been evaluated at MSFC through lab testing to full scale hotfire engine testing of the J-2X Upper Stage engine at Stennis Space Center. It has been shown to provide reliable measurement data and has replaced many traditional measurement techniques for NASA applications. NASA and AMRDEC have recently signed agreements for NASA to train and transition the technology to applications for missile and helicopter testing. This presentation will provide an overview and progression of the technology, various testing applications at NASA MSFC, overview of Army-NASA test collaborations and application lessons learned about Digital Image Correlation.

  19. Pilot study of 3D image correlation photogrammetry to assess strain and deformation of mouthguard materials.

    Science.gov (United States)

    McGlumphy, Kellye C; Mendel, Deborah A; Yilmaz, Burak; Seidt, Jeremy D

    2014-06-01

    The purpose of this investigation was to conduct a pilot study to evaluate the use of 3D image correlation photogrammetry (3DIC) in comparing strain characteristics of three commercially available mouthguard materials in the actual form of a mouthguard. 3DIC was used to measure strain and deformation on the surface of a mouthguard and a resin model. A computed tomographic scan of a maxilla of a patient was used to fabricate a resin test model. Three mouthguard materials were tested: conventional ethylene vinyl acetate; Proform TM, a thermoplastic material; and Polyshok TM, an EVA product containing polyurethane. Three mouthguards of each of the three materials were fabricated and fitted to the acrylic model for testing. A speckle pattern was applied to the external surfaces of each of the mouthguards. Static mechanical tests using a servohydraulic load frame at 10, 25, and 50 pounds of force were applied to the mouthguards while on the resin model. Strains were measured in both the horizontal (x) and vertical (y) axes using (3DIC). Measured strains were analysed by 4-way anova. For all three materials tested, the difference in strain between two measured directions (X and Y) was found to be statistically significant for all regions evaluated. The analysis indicated that each direction, region, and load was involved in a statistically significant effect (P materials. Differences in strains in two directions were found to be significant for the materials studied (P materials in the actual form of a mouthguard. Materials, along with larger sample sizes, may improve confidence levels of the results. Further testing is indicated before clinical claims can be made. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Optical Measurement of In-plane Elastic Waves in Mechanical Metamaterials Through Digital Image Correlation

    CERN Document Server

    Schaeffer, Marshall; Ruzzene, Massimo

    2016-01-01

    We report on a Digital Image Correlation-based technique for the detection of in-plane elastic waves propagating in structural lattices. The experimental characterization of wave motion in lattice structures is currently of great interest due its relevance to the design of novel mechanical metamaterials with unique/unusual properties such as strongly directional behavior, negative refractive indexes and topologically protected wave motion. Assessment of these functionalities often requires the detection of highly spatially resolved in-plane wavefields, which for reticulated or porous structural assemblies is an open challenge. A Digital Image Correlation approach is implemented that tracks small displacements of the lattice nodes by centering image subsets about the lattice intersections. A high speed camera records the motion of the points by properly interleaving subsequent frames thus artificially enhancing the available sampling rate. This, along with an imaging stitching procedure, enables the capturing ...

  1. Resolution of ghost imaging with entangled photons for different types of momentum correlation

    Science.gov (United States)

    Zhong, MaLin; Xu, Ping; Lu, LiangLiang; Zhu, ShiNing

    2016-07-01

    We present an analytical analysis of the spatial resolution of quantum ghost imaging implemented by entangled photons from a general, spontaneously parametric, down-conversion process. We find that the resolution is affected by both the pump beam waist and the nonlinear crystal length. Hence, we determined a method to improve the resolution for a certain imaging setup. It should be noted that the resolution is not uniquely related to the degree of entanglement of the photon pair since the resolution can be optimized for a certain degree of entanglement. For certain types of Einstein-Podolsky-Rosen (EPR) states——namely the momentum-correlated or momentum-positively correlated states——the resolution exhibits a simpler relationship with the pump beam waist and crystal length. Further, a vivid numerical simulation of ghost imaging is presented for different types of EPR states, which supports our analysis. This work discusses applicable references to the applications of quantum ghost imaging.

  2. Expectations Among Academic Clinicians of Inpatient Imaging Turnaround Time: Does it Correlate with Satisfaction?

    Science.gov (United States)

    Chan, Keith T; Carroll, Tamara; Linnau, Ken F; Lehnert, Bruce

    2015-11-01

    Imaging report turnaround time (RTAT) is an important measure of radiology performance and has become the leading priority in customer satisfaction surveys conducted among nonradiologists, who may not be familiar with the imaging workflow. Our aim was to assess physicians' expected RTAT for commonly ordered studies and determine if satisfaction correlates with met expectations. Retrospective review of inpatient imaging was conducted at a single academic institution, and RTAT for 18,414 studies was calculated. Examinations were grouped by study type, priority, and time of day. A cross-sectional survey instrument was completed by 48 internal medicine and surgery resident physicians with questions regarding RTAT and their level of satisfaction with various examinations. Actual RTAT ranged from 1.6 to 26.0 hours, with chest radiographs and computed tomographies generally faster than magnetic resonance images and ultrasounds. Urgent (STAT) examinations and those ordered during business hours have shorter RTAT. The time for image interpretation largely contributed to the RTAT because of the lack of night-time radiology coverage. Referring physician expectations were consistently shorter than actual RTAT, ranging from 30 minutes to 24 hours. Overall satisfaction scores were inversely correlated with RTAT, with a strong correlation to the time from study order to imaging (r(2) = 0.63) and a weak correlation to the image interpretation time (r(2) = 0.17). Satisfaction scores did not correlate with whether the actual RTAT met expectations (r(2) = 0.06). Referring physician satisfaction is likely multifactorial. Although RTAT has been reported as a priority, shortening turnaround time alone may not directly improve clinician satisfaction. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  3. Novel approach to improve molecular imaging research: Correlation between macroscopic and molecular pathological findings in patients

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Ingrid, E-mail: i.boehm@uni-bonn.de [Department of Diagnostic Radiology, ZARF Project, Center for Molecular Imaging Research MBMB, Philipps University of Marburg, Baldingerstrasse, 35039 Marburg (Germany)

    2011-09-15

    Purpose: Currently, clinical research approaches are sparse in molecular imaging studies. Moreover, possible links between imaging features and pathological laboratory parameters are unknown, so far. Therefore, the goal was to find a possible relationship between imaging features and peripheral blood cell apoptosis, and thereby to present a novel way to complement molecular imaging research. Materials and methods: The investigation has been done in systemic lupus erythematosus (SLE), a prototype of an autoimmune disease characterized by multiorgan involvement, autoantibody production, and disturbed apoptosis. Retrospectively, radiological findings have been compared to both autoantibody findings and percentage apoptotic blood cells. Results: Two SLE groups could be identified: patients with normal (annexin V binding < 20%), and with increased apoptosis (annexin V binding > 20%) of peripheral blood cells. The frequency of radiological examinations in SLE patients significantly correlated with an increased percentage of apoptotic cells (p < 0.005). In patients with characteristic imaging findings (e.g. lymph node swelling, pleural effusion) an elevated percentage of apoptotic cells was present. In contrast SLE-patients with normal imaging findings or uncharacteristic results of minimal severity had normal percentages of apoptotic blood cells. Conclusion: This correlation between radiographic findings and percentage of apoptotic blood cells provides (1) further insight into pathological mechanisms of SLE, (2) will offer the possibility to introduce apoptotic biomarkers as molecular probes for clinical molecular imaging approaches in future to early diagnose organ complaints in patients with SLE, and (3) is a plea to complement molecular imaging research by this clinical approach.

  4. Estimation of glacier surface motion by robust phase correlation and point like features of SAR intensity images

    Science.gov (United States)

    Fang, Li; Xu, Yusheng; Yao, Wei; Stilla, Uwe

    2016-11-01

    For monitoring of glacier surface motion in pole and alpine areas, radar remote sensing is becoming a popular technology accounting for its specific advantages of being independent of weather conditions and sunlight. In this paper we propose a method for glacier surface motion monitoring using phase correlation (PC) based on point-like features (PLF). We carry out experiments using repeat-pass TerraSAR X-band (TSX) and Sentinel-1 C-band (S1C) intensity images of the Taku glacier in Juneau icefield located in southeast Alaska. The intensity imagery is first filtered by an improved adaptive refined Lee filter while the effect of topographic reliefs is removed via SRTM-X DEM. Then, a robust phase correlation algorithm based on singular value decomposition (SVD) and an improved random sample consensus (RANSAC) algorithm is applied to sequential PLF pairs generated by correlation using a 2D sinc function template. The approaches for glacier monitoring are validated by both simulated SAR data and real SAR data from two satellites. The results obtained from these three test datasets confirm the superiority of the proposed approach compared to standard correlation-like methods. By the use of the proposed adaptive refined Lee filter, we achieve a good balance between the suppression of noise and the preservation of local image textures. The presented phase correlation algorithm shows the accuracy of better than 0.25 pixels, when conducting matching tests using simulated SAR intensity images with strong noise. Quantitative 3D motions and velocities of the investigated Taku glacier during a repeat-pass period are obtained, which allows a comprehensive and reliable analysis for the investigation of large-scale glacier surface dynamics.

  5. Maximizing setup accuracy using portal images as applied to a conformal boost technique for prostatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bijhold, J.; Lebesque, J.V.; Hart, A.A.M.; Vijlbrief, R.E. (Nederlands Kanker Inst. ' Antoni van Leeuwenhoekhuis' , Amsterdam (Netherlands))

    1992-08-01

    A design procedure of a patients setup verification protocol based upon frequent digital acquisition of portal images is demonstrated with an application for conformal prostatic boost fields. The protocol aims at the elimination of large systematic deviations in the patient setup and includes decision rules which indicate when correction of the patient setup is needed. The decision rules were derived from the results of a theoretical and quantitative analysis of patient setup variations measured in three pelvic fields (one anterior-posterior and two lateral fields) of 105 fractions for nine patients. Deviations in the patients positioning, derived from one field, were quantified as two-dimensional (2-D) displacement vectors in the plane perpendicular to the beam axis by alignment of anatomical features in the portal and the simulator image. The magnitude of the overall setup variations along the anterior-posterior, superior-inferior and lateral directions varied between 2.6 and 3 mm (1 S.D). In addition, intra-treatment variations appeared to be predictable which was a prerequisite for the development of the decision rules. The 2-D setup deviations, measured in three fields of one fraction were strongly correlated and a 3-D displacement vector was calculated. Utilization of this 3-D vector in a setup verification protocol may lead to an early detection of systematic setup deviations. (author). 19 refs., 5 figs., 3 tabs.

  6. High Dynamic Range Particle Image Velocimetry Applied to Heat Convection Studies

    Directory of Open Access Journals (Sweden)

    Persoons Tim

    2014-03-01

    Full Text Available Convective heat transfer occurs in a wide range of engineering applications, from nuclear reactors to portable electronic devices. Accurate whole-field turbulence and flow measurements are crucial to understanding convective heat transfer in complex flow fields, thereby enabling optimal design of these devices. Particle image velocimetry (PIV is the preferred whole-field flow measurement technique. However in many configurations the dynamic velocity range of conventional PIV is too limited to accurately resolve both high mean velocities and turbulence intensities in lower velocity regions. This paper employs high dynamic range (HDR PIV with an advanced acquisition and processing technique based on multiple pulse separation (MPS double-frame imaging. The methodology uses a conventional adaptive multi-grid algorithm for vector evaluation, and determines the optimal pulse separation in space and time in a post-processing routine. Two test cases are discussed: For an impinging synthetic jet flow (Case I, HDR PIV increases the dynamic velocity range 25-fold compared to conventional PIV. For an oscillatory buoyant plume from a pair of horizontal heated cylinders (Case II, the dynamic velocity range is increased 5.5 times. This technique has yielded new insights in synthetic jet heat transfer by correlating local surface heat transfer rates to near-wall turbulence intensity in a single whole-field measurement.

  7. Phase incremented echo train acquisition applied to magnetic resonance pore imaging

    Science.gov (United States)

    Hertel, S. A.; Galvosas, P.

    2017-02-01

    Efficient phase cycling schemes remain a challenge for NMR techniques if the pulse sequences involve a large number of rf-pulses. Especially complex is the Carr Purcell Meiboom Gill (CPMG) pulse sequence where the number of rf-pulses can range from hundreds to several thousands. Our recent implementation of Magnetic Resonance Pore Imaging (MRPI) is based on a CPMG rf-pulse sequence in order to refocus the effect of internal gradients inherent in porous media. While the spin dynamics for spin- 1 / 2 systems in CPMG like experiments are well understood it is still not straight forward to separate the desired pathway from the spectrum of unwanted coherence pathways. In this contribution we apply Phase Incremented Echo Train Acquisition (PIETA) to MRPI. We show how PIETA offers a convenient way to implement a working phase cycling scheme and how it allows one to gain deeper insights into the amplitudes of undesired pathways.

  8. Applying fluorescence lifetime imaging microscopy to evaluate the efficacy of anticancer drugs

    Science.gov (United States)

    Kawanabe, Satoshi; Araki, Yoshie; Uchimura, Tomohiro; Imasaka, Totaro

    2015-06-01

    Fluorescence lifetime imaging microscopy was applied to evaluate the efficacy of anticancer drugs. A decrease in the fluorescence lifetime of the nucleus in apoptotic cancer cells stained by SYTO 13 dye was detected after treatment with antitumor antibiotics such as doxorubicin or epirubicin. It was confirmed that the change in fluorescence lifetime occurred earlier than morphological changes in the cells. We found that the fluorescence lifetime of the nucleus in the cells treated with epirubicin decreased more rapidly than that of the cells treated with doxorubicin. This implies that epirubicin was more efficacious than doxorubicin in the treatment of cancer cells. The change in fluorescence lifetime was, however, not indicated when the cells were treated with cyclophosphamide. The decrease in fluorescence lifetime was associated with the processes involving caspase activation and chromatin condensation. Therefore, this technique would provide useful information about apoptotic cells, particularly in the early stages.

  9. Added clinical value of applying myocardial deformation imaging to assess right ventricular function.

    Science.gov (United States)

    Sokalskis, Vladislavs; Peluso, Diletta; Jagodzinski, Annika; Sinning, Christoph

    2017-06-01

    Right heart dysfunction has been found to be a strong prognostic factor predicting adverse outcome in various cardiopulmonary diseases. Conventional echocardiographic measurements can be limited by geometrical assumptions and impaired reproducibility. Speckle tracking-derived strain provides a robust quantification of right ventricular function. It explicitly evaluates myocardial deformation, as opposed to tissue Doppler-derived strain, which is computed from tissue velocity gradients. Right ventricular longitudinal strain provides a sensitive tool for detecting right ventricular dysfunction, even at subclinical levels. Moreover, the longitudinal strain can be applied for prognostic stratification of patients with pulmonary hypertension, pulmonary embolism, and congestive heart failure. Speckle tracking-derived right atrial strain, right ventricular longitudinal strain-derived mechanical dyssynchrony, and three-dimensional echocardiography-derived strain are emerging imaging parameters and methods. Their application in research is paving the way for their clinical use. © 2017, Wiley Periodicals, Inc.

  10. Image patch analysis of sunspots and active regions. I. Intrinsic dimension and correlation analysis

    CERN Document Server

    Moon, Kevin R; Delouille, Veronique; De Visscher, Ruben; Watson, Fraser; Hero, Alfred O

    2015-01-01

    Complexity of an active region is related to its flare-productivity. Mount Wilson or McIntosh sunspot classifications measure such complexity but in a categorical way, and may therefore not use all the information present in the observations. Moreover, such categorical schemes hinder a systematic study of an active region's evolution for example. We propose fine-scale quantitative descriptors for an active region's complexity and relate them to the Mount Wilson classification. We analyze the local correlation structure within continuum and magnetogram data, as well as the cross-correlation between continuum and magnetogram data. We compute the intrinsic dimension, partial correlation, and canonical correlation analysis (CCA) of image patches of continuum and magnetogram active region images taken from the SOHO-MDI instrument. We use masks of sunspots derived from continuum as well as larger masks of magnetic active regions derived from the magnetogram to analyze separately the core part of an active region fr...

  11. Optimum method of applying and removing a shaped-function signal for low-light-level image detection.

    Science.gov (United States)

    Li, Gang; Zhao, Longfei; Zhou, Mei; Wang, Mengjun; Lin, Ling

    2013-11-20

    This paper presents an optimum method that exploits the principle of diffuse scattering and employs the least squares method (LSM) to apply and remove a shaped-function signal for low-light-level image detection. With the help of a sawtooth-shaped-function light signal applied to an image sensor, the LSM is employed to remove the sawtooth signal from the captured images and restore the weak image signal. The experiment process and result verify that this method can not only maintain the capability of upgrading the image sensor's sensitivity and signal-to-noise ratio like the previous method, but it also can improve the imaging speed in the low-light level, decrease the computation cost of the extraction process, and eliminate the influence of the environment light to satisfy the requirement of long-distance detection.

  12. Accuracy Investigation of Creating Orthophotomaps Based on Images Obtained by Applying Trimble-UX5 UAV

    Science.gov (United States)

    Hlotov, Volodymyr; Hunina, Alla; Siejka, Zbigniew

    2017-06-01

    The main purpose of this work is to confirm the possibility of making largescale orthophotomaps applying unmanned aerial vehicle (UAV) Trimble- UX5. A planned altitude reference of the studying territory was carried out before to the aerial surveying. The studying territory has been marked with distinctive checkpoints in the form of triangles (0.5 × 0.5 × 0.2 m). The checkpoints used to precise the accuracy of orthophotomap have been marked with similar triangles. To determine marked reference point coordinates and check-points method of GNSS in real-time kinematics (RTK) measuring has been applied. Projecting of aerial surveying has been done with the help of installed Trimble Access Aerial Imaging, having been used to run out the UX5. Aerial survey out of the Trimble UX5 UAV has been done with the help of the digital camera SONY NEX-5R from 200m and 300 m altitude. These aerial surveying data have been calculated applying special photogrammetric software Pix 4D. The orthophotomap of the surveying objects has been made with its help. To determine the precise accuracy of the got results of aerial surveying the checkpoint coordinates according to the orthophotomap have been set. The average square error has been calculated according to the set coordinates applying GNSS measurements. A-priori accuracy estimation of spatial coordinates of the studying territory using the aerial surveying data have been calculated: mx=0.11 m, my=0.15 m, mz=0.23 m in the village of Remeniv and mx=0.26 m, my=0.38 m, mz=0.43 m in the town of Vynnyky. The accuracy of determining checkpoint coordinates has been investigated using images obtained out of UAV and the average square error of the reference points. Based on comparative analysis of the got results of the accuracy estimation of the made orthophotomap it can be concluded that the value the average square error does not exceed a-priori accuracy estimation. The possibility of applying Trimble UX5 UAV for making large

  13. Early Detection of Breast Cancer via Multi-plane Correlation Breast Imaging

    Science.gov (United States)

    2008-04-01

    changing the acquisi- tion scheme on the performance of CI and are expected to correlate with the base line detection performance of a clini- cian using...in this study may serve as guide- lines for optimizing the acquisition parameters and dose for any multiprojection imaging system. V. CONCLUSIONS In...improved detection of lung nodules,” Proc. SPIE 5030, 284–297 2003. 8E. Samei, S. A. Stebbins , J. T. Dobbins, and J. Y. Lo, “Multiprojection correlation

  14. Spatio-Chromatic Adaptation via Higher-Order Canonical Correlation Analysis of Natural Images

    OpenAIRE

    Gutmann, Michael U.; Valero Laparra; Aapo Hyvärinen; Jesús Malo

    2014-01-01

    Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes...

  15. Correlation of bone quality in radiographic images with clinical bone quality classification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Woo; Huh, Kyung Hoe; Kim, Jeong Hwa; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Seoul National University, Seoul (Korea, Republic of); Park, Kwan Soo [Inje University, Seoul (Korea, Republic of)

    2006-03-15

    To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined in each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and -0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlating with clinical bone quality classification with correlation coefficients -0.506 significantly (P<0.05). This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.

  16. Land use mapping from CBERS-2 images with open source tools by applying different classification algorithms

    Science.gov (United States)

    Sanhouse-García, Antonio J.; Rangel-Peraza, Jesús Gabriel; Bustos-Terrones, Yaneth; García-Ferrer, Alfonso; Mesas-Carrascosa, Francisco J.

    2016-02-01

    Land cover classification is often based on different characteristics between their classes, but with great homogeneity within each one of them. This cover is obtained through field work or by mean of processing satellite images. Field work involves high costs; therefore, digital image processing techniques have become an important alternative to perform this task. However, in some developing countries and particularly in Casacoima municipality in Venezuela, there is a lack of geographic information systems due to the lack of updated information and high costs in software license acquisition. This research proposes a low cost methodology to develop thematic mapping of local land use and types of coverage in areas with scarce resources. Thematic mapping was developed from CBERS-2 images and spatial information available on the network using open source tools. The supervised classification method per pixel and per region was applied using different classification algorithms and comparing them among themselves. Classification method per pixel was based on Maxver algorithms (maximum likelihood) and Euclidean distance (minimum distance), while per region classification was based on the Bhattacharya algorithm. Satisfactory results were obtained from per region classification, where overall reliability of 83.93% and kappa index of 0.81% were observed. Maxver algorithm showed a reliability value of 73.36% and kappa index 0.69%, while Euclidean distance obtained values of 67.17% and 0.61% for reliability and kappa index, respectively. It was demonstrated that the proposed methodology was very useful in cartographic processing and updating, which in turn serve as a support to develop management plans and land management. Hence, open source tools showed to be an economically viable alternative not only for forestry organizations, but for the general public, allowing them to develop projects in economically depressed and/or environmentally threatened areas.

  17. Infantile fibromatosis in childhood: Findings on MR imaging and pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joong Mo; Yoon, Hye-Kyung; Suh, Yeon-Lim; Kim, Eung Yeop; Han, Bokyung K.; Yoon, Jung Hwan; Kim, Seung Hoon; Cho Jae Min; Kim, Sung; Moon; Kang, Heung Sik

    2000-01-01

    AIM: The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features. MATERIALS AND METHODS: Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features. RESULTS: On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable. CONCLUSION: Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change. Ahn, J.M. (2000)

  18. Validation of Shape Context Based Image Registration Method Using Digital Image Correlation Measurement on a Rat Stomach

    DEFF Research Database (Denmark)

    Liao, Donghua; Wang, P; Zhao, Jingbo

    2014-01-01

    needs to be further verified by using a feature tracking measurement. Hence, the aim of this study was to verify the SC method-based calculation by using digital image correlation (DIC) measurement on a rat stomach. The rat stomach exposed to distension pressures 0.0, 0.2, 0.4, and 0.6 kPa were studied...... and quantitative agreement on the surfaces with small dissimilarity and small sample count difference between the reference surface and the target surface. In conclusion, this is the first study to validate the 3D SC-based image registration method by using unique tracking features measurement. The developed...

  19. Accurate kinematic measurement at interfaces between dissimilar materials using conforming finite-element-based digital image correlation

    KAUST Repository

    Tao, Ran

    2016-02-11

    Digital image correlation (DIC) is now an extensively applied full-field measurement technique with subpixel accuracy. A systematic drawback of this technique, however, is the smoothening of the kinematic field (e.g., displacement and strains) across interfaces between dissimilar materials, where the deformation gradient is known to be large. This can become an issue when a high level of accuracy is needed, for example, in the interfacial region of composites or joints. In this work, we described the application of global conforming finite-element-based DIC technique to obtain precise kinematic fields at interfaces between dissimilar materials. Speckle images from both numerical and actual experiments processed by the described global DIC technique better captured sharp strain gradient at the interface than local subset-based DIC. © 2016 Elsevier Ltd. All rights reserved.

  20. Double-image encryption based on joint transform correlation and phase-shifting interferometry

    Institute of Scientific and Technical Information of China (English)

    Lina Shen; Jun Li; Hongsen Chang

    2007-01-01

    An image encryption method combining the joint transform correlator (JTC) architecture with phaseshifting interferometry to realize double random-phase encoding is proposed. The encrypted field and the decrypting key are registered as holograms by phase-shifting interferometry. This method can encrypt two images simultaneously to improve the encryption efficiency of the methods based on JTC architecture, and eliminate the system alignment constraint of the methods based on Mach-Zehnder interferometer (MZI)architecture. Its feasibility and validity are verified by computer simulations. Moreover, image encryption and decryption can be achieved at high speed optically or digitally. The encrypted data are suitable for Internet transmission.

  1. Correlation between Health Perception, Body Image, and Eating Habits in High School Students

    Directory of Open Access Journals (Sweden)

    Abdullah Ichsan

    2016-06-01

    Full Text Available Background: Mental disorders, including eating disorders, mostly begin during youth. Moreover, negative body image is found to cause unhealthy eating habits in the context of several cross-cultural settings. This study aimed to examine the correlation between health perception and body image with eating habits among high school students. Methods: A structured, anonymous questionnaire was distributed to students of a private high school in Bandung, Indonesia in June-October 2014. The questionnaire included questions about health perception, body image, eating habits, body weight and height, and also other demographic parameters. The school was selected as the study object through purposive sampling, and 140 high school students (72 male and 68 female were ramdomly selected. Results: Male and female did not show considerable differences in health perceptions. Out of 13 statements, 12 statements of male respondents showed better body image than female. While in eating habits statements, female respondents seemed to maintain healthier eating habits than male respondents. No significant correlation was observed between body image and eating habits (r=-0.015, p=0.858. There was significant correlation between health perception and eating habits (r=0.374, p<0.001. Correlation between sex and eating habits was found (p=0.020, there was not significant relationship between eating habits and Body Mass Index (BMI (p=0.368. Conclusions: The negative relationship between body image and eating habits is not significant. However there was a significant positive relationship between health perception and eating habits. Furthermore, there was correlation between sex and eating habits, while the positive relationship between eating habits and BMI was still not found.

  2. NCI Workshop Report: Clinical and Computational Requirements for Correlating Imaging Phenotypes with Genomics Signatures

    Directory of Open Access Journals (Sweden)

    Rivka Colen

    2014-10-01

    Full Text Available The National Cancer Institute (NCI Cancer Imaging Program organized two related workshops on June 26–27, 2013, entitled “Correlating Imaging Phenotypes with Genomics Signatures Research” and “Scalable Computational Resources as Required for Imaging-Genomics Decision Support Systems.” The first workshop focused on clinical and scientific requirements, exploring our knowledge of phenotypic characteristics of cancer biological properties to determine whether the field is sufficiently advanced to correlate with imaging phenotypes that underpin genomics and clinical outcomes, and exploring new scientific methods to extract phenotypic features from medical images and relate them to genomics analyses. The second workshop focused on computational methods that explore informatics and computational requirements to extract phenotypic features from medical images and relate them to genomics analyses and improve the accessibility and speed of dissemination of existing NIH resources. These workshops linked clinical and scientific requirements of currently known phenotypic and genotypic cancer biology characteristics with imaging phenotypes that underpin genomics and clinical outcomes. The group generated a set of recommendations to NCI leadership and the research community that encourage and support development of the emerging radiogenomics research field to address short-and longer-term goals in cancer research.

  3. Optical image encryption based on a joint Fresnel transform correlator with double optical wedges.

    Science.gov (United States)

    Shen, Xueju; Dou, Shuaifeng; Lei, Ming; Chen, Yudan

    2016-10-20

    An optical cryptosystem based on the joint Fresnel transform correlator (JFTC) with double optical wedges is designed. The designed cryptosystem retains the two major advantages of JTC-based optical cryptosystems. First, the encrypted image is real-valued and therefore is easier to record and transmit. Second, the encryption process is simplified, since it doesn't require accurate alignment of optical elements or the generation of the complex conjugate of the key. Also, the designed optical cryptosystem can produce a decrypted image with higher quality than a JTC-based optical cryptosystem, because the original encrypted image is divided by the Fresnel transform power distribution of the key mask to generate the new encrypted image, which significantly reduces the noise during the decryption process. Simulation results showed that the correlation coefficient of the decrypted image and the original image can reach as large as 0.9819 after denoising and adequately selecting half-central interval a and encrypted image width w. Another improvement relative to JTC-based optical cryptosystems is that the attack resistibility gets enhanced due to the nonlinearity of the encryption process as well as the additional key parameter a, which enlarges the key space.

  4. High-resolution MR imaging of the cutis and subcutis. Histological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Krug, B.; Kugel, H.; Krahe, T.; Lackner, K. [Koeln Univ. (Germany). Radiologisches Inst. und Poliklinik; Schulze, H.J. [Koeln Univ. (Germany). Klinik und Poliklinik fuer Dermatologie und Venerologie; Gieseke, J. [Philips Medical Systems, Hamburg (Germany)

    1998-09-01

    Objective: To determine whether the spatial resolution that can be achieved with currently available MR devices is adequate for the evaluation of skin disease. Material and Methods: We correlated high-resolution MR images of the skin with dermatohistopathology in 26 patients. The examinations were carried out on a 1.0 T imager using a commercially available surface coil (ID 7.5 cm) and optimized SE and GE sequences. Image quality was assessed by four readers on a questionnaire. Results: The visualization of the dermis, subcutaneous tissue, and muscle fascia allowed a pattern analysis that gave findings identical to those at dermatohistopathology. It was possible to distinguish septal from lobular panniculitis, and lipatrophia from sclerodermia. Images with contrast media infusion were useful in the differential diagnosis. Conclusion: High-resolution MR imaging may narrow down the differential diagnosis of various skin diseases and may help to reduce the number of skin biopsies on certain indications. (orig.)

  5. Minimum variance imaging based on correlation analysis of Lamb wave signals.

    Science.gov (United States)

    Hua, Jiadong; Lin, Jing; Zeng, Liang; Luo, Zhi

    2016-08-01

    In Lamb wave imaging, MVDR (minimum variance distortionless response) is a promising approach for the detection and monitoring of large areas with sparse transducer network. Previous studies in MVDR use signal amplitude as the input damage feature, and the imaging performance is closely related to the evaluation accuracy of the scattering characteristic. However, scattering characteristic is highly dependent on damage parameters (e.g. type, orientation and size), which are unknown beforehand. The evaluation error can degrade imaging performance severely. In this study, a more reliable damage feature, LSCC (local signal correlation coefficient), is established to replace signal amplitude. In comparison with signal amplitude, one attractive feature of LSCC is its independence of damage parameters. Therefore, LSCC model in the transducer network could be accurately evaluated, the imaging performance is improved subsequently. Both theoretical analysis and experimental investigation are given to validate the effectiveness of the LSCC-based MVDR algorithm in improving imaging performance.

  6. Efficient content-based low-altitude images correlated network and strips reconstruction

    Science.gov (United States)

    He, Haiqing; You, Qi; Chen, Xiaoyong

    2017-01-01

    The manual intervention method is widely used to reconstruct strips for further aerial triangulation in low-altitude photogrammetry. Clearly the method for fully automatic photogrammetric data processing is not an expected way. In this paper, we explore a content-based approach without manual intervention or external information for strips reconstruction. Feature descriptors in the local spatial patterns are extracted by SIFT to construct vocabulary tree, in which these features are encoded in terms of TF-IDF numerical statistical algorithm to generate new representation for each low-altitude image. Then images correlated network is reconstructed by similarity measure, image matching and geometric graph theory. Finally, strips are reconstructed automatically by tracing straight lines and growing adjacent images gradually. Experimental results show that the proposed approach is highly effective in automatically rearranging strips of lowaltitude images and can provide rough relative orientation for further aerial triangulation.

  7. Multiscale displacement field measurements of compressed mineral-wool samples by digital image correlation

    Science.gov (United States)

    Hild, Francois; Raka, Bumedijen; Baudequin, Maud; Roux, Stephane; Cantelaube, Florence

    2002-11-01

    We propose a multiscale approach to determine the displacement field by digital image correlation. The displacement field is first estimated on a coarse resolution image and progressively finer details are introduced in the analysis as the displacement is more and more securely and accurately determined. Such a scheme has been developed to increase the robustness, accuracy, and reliability of the image-matching algorithm. The procedure is used on two different types of examples. The first one deals with a representative image that is deformed precisely and purposefully to assess the intrinsic performances. In particular, the maximum measurable strain is determined. The second case deals with a series of pictures taken during compression experiments on mineral-wool samples. The different steps of the procedure are analyzed and their respective role is assessed. Both reflection and transmission images are tested.

  8. Observation of a cavitation cloud in tissue using correlation between ultrafast ultrasound images.

    Science.gov (United States)

    Prieur, Fabrice; Zorgani, Ali; Catheline, Stefan; Souchon, Rémi; Mestas, Jean-Louis; Lafond, Maxime; Lafon, Cyril

    2015-07-01

    The local application of ultrasound is known to improve drug intake by tumors. Cavitating bubbles are one of the contributing effects. A setup in which two ultrasound transducers are placed confocally is used to generate cavitation in ex vivo tissue. As the transducers emit a series of short excitation bursts, the evolution of the cavitation activity is monitored using an ultrafast ultrasound imaging system. The frame rate of the system is several thousands of images per second, which provides several tens of images between consecutive excitation bursts. Using the correlation between consecutive images for speckle tracking, a decorrelation of the imaging signal appears due to the creation, fast movement, and dissolution of the bubbles in the cavitation cloud. By analyzing this area of decorrelation, the cavitation cloud can be localized and the spatial extent of the cavitation activity characterized.

  9. Tomography of correlation functions for ultracold atoms via time-of-flight images

    OpenAIRE

    ZHANG, WEI; Duan, L.-M.

    2009-01-01

    We propose to utilize density distributions from a series of time-of-flight images of an expanding cloud to reconstruct single-particle correlation functions of trapped ultra-cold atoms. In particular, we show how this technique can be used to detect off-diagonal correlations of atoms in a quasi-one-dimensional trap, where both real- and momentum- space correlations are extracted at a quantitative level. The feasibility of this method is analyzed with specific examples, taking into account fi...

  10. Damage law identification of a quasi brittle ceramic from a b ending test using digital image correlation

    Directory of Open Access Journals (Sweden)

    Meille S.

    2010-06-01

    Full Text Available The quasi brittle ceramics show a non linear mechanical behaviour resulting most of the time in a dissymetry between their tensile and compressive stress-strain laws. The characterization of their fracture strengths might be biased if elastic linear formulae are used to analyze classical tests like bending tests. Based on Digital Image Correlation (DIC, a methodology is proposed to characterize materials with dissymmetric behaviours. Applying specific DIC decomposition functions for bending, compressive and tensile tests, a stress-strain model and its damage law are identified for aluminium titanate, a damageable micro cracked ceramic. This identification method using DIC can obviously be applied to other quasi brittle materials.

  11. Model-independent source imaging using two-pion correlations in 2 to 8A GeV Au + Au collisions

    CERN Document Server

    Panitkin, S Y; Alexander, J; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D; Chance, J; Chung, P; Cole, B; Crowe, K M; Das, A; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A; Hjort, E; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J; Klay, J L; Krofcheck, D; Lacey, R A; Lauret, J; Lisa, M A; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D; Pinkenburg, C H; Porile, N; Rai, G; Ritter, H G; Romero, J; Scharenberg, R P; Schröder, L S; Srivastava, B; Stone, N T B; Symons, T J M; Wang, S; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Yang, X; Zhang Wei Ning; Zhang, Y

    2001-01-01

    We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au + Au collisions at beam energies between 2 and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional HBT analysis.

  12. Correlation between subcutaneous knee fat thickness and chondromalacia patellae on magnetic resonance imaging of the knee.

    LENUS (Irish Health Repository)

    Kok, Hong Kuan

    2013-08-01

    Chondromalacia patellae is a common cause of anterior knee pain in young patients and can be detected noninvasively with magnetic resonance imaging (MRI). The purpose of our study was to evaluate the correlation between subcutaneous fat thickness around the knee joint on axial MRIs as a surrogate marker of obesity, with the presence or absence of chondromalacia patellae.

  13. Correlating signs and symptoms with pubovisceral muscle avulsions on magnetic resonance imaging

    NARCIS (Netherlands)

    Lammers, K.; Futterer, J.J.; Hout, J. in't; Prokop, M.; Vierhout, M.E.; Kluivers, K.B.

    2013-01-01

    OBJECTIVE: We sought to correlate signs and symptoms of pelvic organ prolapse (POP) with pubovisceral muscle avulsions on magnetic resonance imaging (MRI). STUDY DESIGN: In this retrospective cohort study of 189 women with recurrent POP or unexplained symptoms of pelvic floor dysfunction, we reviewe

  14. Fluorescence lifetime imaging by time-correlated single-photon counting

    NARCIS (Netherlands)

    Becker, W.; Bergmann, A.; Hink, M.A.; Konig, K.; Benndorf, K.; Biskup, C.

    2004-01-01

    We present a time-correlated single photon counting (TCPSC) technique that allows time-resolved multi-wavelength imaging in conjunction with a laser scanning microscope and a pulsed excitation source. The technique is based on a four-dimensional histogramming process that records the photon density

  15. Non-linearly weighted fuzzy correlation for color-image retrieval

    Institute of Scientific and Technical Information of China (English)

    Guoguang Mu(母国光); Hongchen Zhai(翟宏琛); Siyuan Zhang(张思远)

    2003-01-01

    An algorithm with non-linear weight factors in the summation process for fuzzy correlation of color his-tograms is presented, in which non-linear weights are assigned to some characteristic colors of interest.Experimental results show that this can improve the retrieval of color images with partial aberrations orwith local color characters.

  16. Anatomy-Correlated Breast Imaging and Visual Grading Analysis Using Quantitative Transmission Ultrasound™

    Directory of Open Access Journals (Sweden)

    John C. Klock

    2016-01-01

    Full Text Available Objectives. This study presents correlations between cross-sectional anatomy of human female breasts and Quantitative Transmission (QT Ultrasound, does discriminate classifier analysis to validate the speed of sound correlations, and does a visual grading analysis comparing QT Ultrasound with mammography. Materials and Methods. Human cadaver breasts were imaged using QT Ultrasound, sectioned, and photographed. Biopsies confirmed microanatomy and areas were correlated with QT Ultrasound images. Measurements were taken in live subjects from QT Ultrasound images and values of speed of sound for each identified anatomical structure were plotted. Finally, a visual grading analysis was performed on images to determine whether radiologists’ confidence in identifying breast structures with mammography (XRM is comparable to QT Ultrasound. Results. QT Ultrasound identified all major anatomical features of the breast, and speed of sound calculations showed specific values for different breast tissues. Using linear discriminant analysis overall accuracy is 91.4%. Using visual grading analysis readers scored the image quality on QT Ultrasound as better than on XRM in 69%–90% of breasts for specific tissues. Conclusions. QT Ultrasound provides accurate anatomic information and high tissue specificity using speed of sound information. Quantitative Transmission Ultrasound can distinguish different types of breast tissue with high resolution and accuracy.

  17. Anatomy-Correlated Breast Imaging and Visual Grading Analysis Using Quantitative Transmission Ultrasound™

    Science.gov (United States)

    Iuanow, Elaine; Malik, Bilal; Obuchowski, Nancy A.; Wiskin, James

    2016-01-01

    Objectives. This study presents correlations between cross-sectional anatomy of human female breasts and Quantitative Transmission (QT) Ultrasound, does discriminate classifier analysis to validate the speed of sound correlations, and does a visual grading analysis comparing QT Ultrasound with mammography. Materials and Methods. Human cadaver breasts were imaged using QT Ultrasound, sectioned, and photographed. Biopsies confirmed microanatomy and areas were correlated with QT Ultrasound images. Measurements were taken in live subjects from QT Ultrasound images and values of speed of sound for each identified anatomical structure were plotted. Finally, a visual grading analysis was performed on images to determine whether radiologists' confidence in identifying breast structures with mammography (XRM) is comparable to QT Ultrasound. Results. QT Ultrasound identified all major anatomical features of the breast, and speed of sound calculations showed specific values for different breast tissues. Using linear discriminant analysis overall accuracy is 91.4%. Using visual grading analysis readers scored the image quality on QT Ultrasound as better than on XRM in 69%–90% of breasts for specific tissues. Conclusions. QT Ultrasound provides accurate anatomic information and high tissue specificity using speed of sound information. Quantitative Transmission Ultrasound can distinguish different types of breast tissue with high resolution and accuracy.

  18. Increasing accuracy and precision of digital image correlation through pattern optimization

    Science.gov (United States)

    Bomarito, G. F.; Hochhalter, J. D.; Ruggles, T. J.; Cannon, A. H.

    2017-04-01

    The accuracy and precision of digital image correlation (DIC) is based on three primary components: image acquisition, image analysis, and the subject of the image. Focus on the third component, the image subject, has been relatively limited and primarily concerned with comparing pseudo-random surface patterns. In the current work, a strategy is proposed for the creation of optimal DIC patterns. In this strategy, a pattern quality metric is developed as a combination of quality metrics from the literature rather than optimization based on any single one of them. In this way, optimization produces a pattern which balances the benefits of multiple quality metrics. Specifically, sum of square of subset intensity gradients (SSSIG) was found to be the metric most strongly correlated to DIC accuracy and thus is the main component of the newly proposed pattern quality metric. A term related to the secondary auto-correlation peak height is also part of the proposed quality metric which effectively acts as a constraint upon SSSIG ensuring that a regular (e.g., checkerboard-type) pattern is not achieved. The combined pattern quality metric is used to generate a pattern that was on average 11.6% more accurate than a randomly generated pattern in a suite of numerical experiments. Furthermore, physical experiments were performed which confirm that there is indeed improvement of a similar magnitude in DIC measurements for the optimized pattern compared to a random pattern.

  19. A new analysis method for very high definition Imaging Atmospheric Cherenkov Telescopes as applied to the CAT telescope

    CERN Document Server

    Le Bohec, S; Punch, M; Barrau, A; Bazer-Bachi, R; Cabot, H; Chounet, L M; Debiais, G; Dezalay, J P; Djannati-Ataï, A; Dumora, D; Espigat, P; Fabre, B; Fleury, P; Fontaine, G; George, R; Ghesquière, C; Goret, P; Gouiffes, C; Grenier, I A; Iacoucci, L; Malet, I; Meynadier, C; Munz, F; Palfrey, T A; Paré, E; Pons, Y; Québert, J; Ragan, K; Renault, C; Rivoal, M; Rob, L; Schovanek, P; Smith, D; Tavernet, J P; Vrana, J

    1998-01-01

    A new method of shower-image analysis is presented which appears very powerful as applied to those Cherenkov Imaging Telescopes with very high definition imaging capability. It provides hadron rejection on the basis of a single cut on the image shape, and simultaneously determines the energy of the electromagnetic shower and the position of the shower axis with respect to the detector. The source location is also reconstructed for each individual gamma-ray shower, even with one single telescope, so for a point source the hadron rejection can be further improved. As an example, this new method is applied to data from the CAT (Cherenkov Array at Themis) imaging telescope, which has been operational since Autumn, 1996.

  20. Visualizing functional pathways in the human brain using correlation tensors and magnetic resonance imaging.

    Science.gov (United States)

    Ding, Zhaohua; Xu, Ran; Bailey, Stephen K; Wu, Tung-Lin; Morgan, Victoria L; Cutting, Laurie E; Anderson, Adam W; Gore, John C

    2016-01-01

    Functional magnetic resonance imaging usually detects changes in blood oxygenation level dependent (BOLD) signals from T2*-sensitive acquisitions, and is most effective in detecting activity in brain cortex which is irrigated by rich vasculature to meet high metabolic demands. We recently demonstrated that MRI signals from T2*-sensitive acquisitions in a resting state exhibit structure-specific temporal correlations along white matter tracts. In this report we validate our preliminary findings and introduce spatio-temporal functional correlation tensors to characterize the directional preferences of temporal correlations in MRI signals acquired at rest. The results bear a remarkable similarity to data obtained by diffusion tensor imaging but without any diffusion-encoding gradients. Just as in gray matter, temporal correlations in resting state signals may reflect intrinsic synchronizations of neural activity in white matter. Here we demonstrate that functional correlation tensors are able to visualize long range white matter tracts as well as short range sub-cortical fibers imaged at rest, and that evoked functional activities alter these structures and enhance the visualization of relevant neural circuitry. Furthermore, we explore the biophysical mechanisms underlying these phenomena by comparing pulse sequences, which suggest that white matter signal variations are consistent with hemodynamic (BOLD) changes associated with neural activity. These results suggest new ways to evaluate MRI signal changes within white matter. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Synthetic aperture radar image correlation by use of preprocessing for enhancement of scattering centers.

    Science.gov (United States)

    Khoury, J; Gianino, P D; Woods, C L

    2000-10-15

    We demonstrate that a significant improvement can be obtained in the recognition of complicated synthetic aperture radar images taken from the Moving and Stationary Target Acquisitions and Recognition database. These images typically have a low number of scattering centers and high noise. We first preprocess the images and the templates formed from them so that their scattering centers are enhanced. Our technique can produce high-quality performance in several correlation criteria. For realistic automatic target recognition systems, our approach should make it easy to implement optical recognition systems with binarized data for many different types of correlation filter and should have a great effect on feeding data-compressed (binarized) information into either digital or optical processors.

  2. MEASURING SEA ICE DRIFT VIA CROSS-CORRELATION OF RADAR ICE IMAGES

    Institute of Scientific and Technical Information of China (English)

    SUN He-quan; SHEN Yong-ming; Qiu Da-hong

    2004-01-01

    The motion of sea ice has a great effect on winter navigation, and oil field exploration in the Bohai Sea. It is very important to measure the ice drift accurately and efficiently. As a practical technique, radar imagery has been used for sea ice monitoring and forecasting for a long time. Combining with the radar imagery and cross-correlation technique, a new measurement method based on the cross-correlation of radar ice images is specified in this paper to obtain full field measurement of sea ice drift. The theory and fast implementation of cross-correlation are presented briefly in the paper, including the filtering method to modify the invalid vectors. To show deeply the validity of the present method, the velocity maps of sea ice drift are provided in the paper, which are calculated from the radar images grabbed in the Liaodong Gulf. The comparison with the traditional tracing method is also conducted.

  3. Vibration of low amplitude imaged in amplitude and phase by sideband versus carrier correlation digital holography

    CERN Document Server

    Verrier, N; Gross, M

    2015-01-01

    Sideband holography can be used to get fields images (E0 and E1) of a vibrating object for both the carrier (E0) and the sideband (E1) frequency with respect to vibration. We propose here to record E0 and E1 sequentially, and to image the correlation E1E * 0 . We show that this correlation is insensitive the phase related to the object roughness and directly reflect the phase of the mechanical motion. The signal to noise can be improved by averaging the correlation over neighbor pixel. Experimental validation is made with vibrating cube of wood and with a clarinet reed. At 2 kHz, vibrations of amplitude down to 0.01 nm are detected.

  4. Magnetic Resonance Imaging of Breast Cancer and Correlation with Prognostic Factors

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yun-Woo; Kwon, Kui Hyang; Choi, Deuk Lin; Lee, Dong Wha; Lee, Min Hyuk (College of Medicine, Soonchunhyang Univ. Hospital, Seoul (Korea)); Lee, Hye Kyung (Dept. of Radiology, Soonchunhyang Bucheon Hospital, Kyonggi (Korea)); Yang, Seung Boo (Dept. of Radiology, Soonchunhyang Gumi Hospital, Kyungbook (Korea)); Kim, Yongbae (Dept. of Preventive Medicine, Soonchunhyang Univ., Chungnam (Korea)); Seo, Dae Young (Dept. of Computer Engineering (KO) Polytechnic Univ., Kyonggi (Korea))

    2009-11-15

    Background: Prognostic factors of breast cancer have been used for the prediction of clinical outcome or selection of patients for complementary treatment. Some of the imaging features of breast cancer, e.g. magnetic resonance imaging (MRI), are associated with these prognostic factors. Purpose: To evaluate the relationship between dynamic enhanced MR features and prognostic factors of clinical outcome of breast cancer. Material and Methods: A total of 136 patients with 151 breast cancers underwent 1.5T dynamic MR imaging with the use of a dynamic T1-weighted three-dimensional fast low-angle shot (FLASH) subtraction imaging technique. Morphological and kinetic analyses of MR features were evaluated using the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) MRI lexicon. Pathological prognostic factors were correlated with MR imaging characteristics, including tumor size, histological grade, lymph node status, expression of estrogen receptor (ER), expression of progesterone receptor (PR), expression of c-erbB2, determination of Ki-67 index, and microvascular density (MVD), using univariate and multivariate statistical analyses. Results: Based on univariate and multivariate analyses, spiculated tumor margins correlated significantly with lower histological grade (I-II) and positive PR expression. Rim enhancement was significantly correlated with high histological grade, presence of axillary lymph node metastasis, large tumor size, increased Ki-67 index, and increased MVD. Early peak enhancement, as seen on the first scan after contrast medium injection, was correlated with negative ER expression. Conclusion: The presence of a lesion with a spiculated margin may predict a relatively good prognosis, and the presence of a lesion with rim enhancement may predict a relatively poor prognosis

  5. Generalizing the correlated chromophore domain model of reversible photodegradation to include the effects of an applied electric field

    CERN Document Server

    Anderson, Benjamin

    2013-01-01

    All observations of photodegradation and self healing follow the predictions of the correlated chromophore domain model. [Ramini et.al. Polym. Chem., 2013, 4, 4948.] In the present work, we generalize the domain model to describe the effects of an electric field by including induced dipole interactions between molecules in a domain by means of a self-consistent field approach. This electric field correction is added to the statistical mechanical model to calculate the distribution of domains that are central to healing. Also included in the model are the dynamics due to the formation of an irreversibly damaged species. As in previous studies, the model with a one-dimensional domain best explains all experimental data of the population as a function of time, temperature, intensity, concentration, and now applied electric field. Though the nature of a domain is yet to be determined, the fact that only one-dimensional domain models are consistent with observations suggests that they might be made of correlated d...

  6. Fully phase color image encryption based on joint fractional Fourier transform correlator and phase retrieval algorithm

    Institute of Scientific and Technical Information of China (English)

    Ding Lu; Weimin Jin

    2011-01-01

    A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption.The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.%@@ A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption. The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.

  7. A novel fractal image compression scheme with block classification and sorting based on Pearson's correlation coefficient.

    Science.gov (United States)

    Wang, Jianji; Zheng, Nanning

    2013-09-01

    Fractal image compression (FIC) is an image coding technology based on the local similarity of image structure. It is widely used in many fields such as image retrieval, image denoising, image authentication, and encryption. FIC, however, suffers from the high computational complexity in encoding. Although many schemes are published to speed up encoding, they do not easily satisfy the encoding time or the reconstructed image quality requirements. In this paper, a new FIC scheme is proposed based on the fact that the affine similarity between two blocks in FIC is equivalent to the absolute value of Pearson's correlation coefficient (APCC) between them. First, all blocks in the range and domain pools are chosen and classified using an APCC-based block classification method to increase the matching probability. Second, by sorting the domain blocks with respect to APCCs between these domain blocks and a preset block in each class, the matching domain block for a range block can be searched in the selected domain set in which these APCCs are closer to APCC between the range block and the preset block. Experimental results show that the proposed scheme can significantly speed up the encoding process in FIC while preserving the reconstructed image quality well.

  8. Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Bredella, M.A.; Wischer, T.K.; Stork, A.; Genant, H.K. [Dept. of Radiology, University of California, San Francisco (United States); Tirman, P.F.J. [San Francisco Magnetic Resonance Center, CA (United States); Fritz, R.C. [National Orthopaedic Imaging Associates, Greenbrae, CA (United States)

    1999-10-01

    Objective. To investigate the use of MR imaging in the characterization of denervated muscle of the shoulder correlated with electrophysiologic studies.Design and patients. We studied with MR imaging five patients who presented with shoulder weakness and pain and who underwent electrophysiologic studies. On MR imaging the distribution of muscle edema and fatty infiltration was recorded, as was the presence of masses impinging on a regional nerve.Results. Acute/subacute denervation was best seen on T2-weighted fast spin-echo images with fat saturation, showing increased SI related to neurogenic edema. Chronic denervation was best seen on T1-weighted spin-echo images, demonstrating loss of muscle bulk and diffuse areas of increased signal intensity within the muscle. Three patients showed MR imaging and electrophysiologic findings of Parsonage Turner syndrome. One patient demonstrated an arteriovenous malformation within the spinoglenoid notch, impinging on the suprascapular nerve with associated atrophy of the infraspinatus muscle. The fifth patient demonstrated fatty atrophy of the teres minor muscle caused by compression by a cyst of the axillary nerve and electrophysiologic findings of an incomplete axillary nerve block.Conclusion. MR imaging is useful in detecting and characterizing denervation atrophy and neurogenic edema in shoulder muscles. MR imaging can provide additional information to electrophysiologic studies by estimating the age (acute/chronic) and identifying morphologic causes for shoulder pain and atrophy. (orig.)

  9. Computational assessment of mammography accreditation phantom images and correlation with human observer analysis

    Science.gov (United States)

    Barufaldi, Bruno; Lau, Kristen C.; Schiabel, Homero; Maidment, D. A.

    2015-03-01

    Routine performance of basic test procedures and dose measurements are essential for assuring high quality of mammograms. International guidelines recommend that breast care providers ascertain that mammography systems produce a constant high quality image, using as low a radiation dose as is reasonably achievable. The main purpose of this research is to develop a framework to monitor radiation dose and image quality in a mixed breast screening and diagnostic imaging environment using an automated tracking system. This study presents a module of this framework, consisting of a computerized system to measure the image quality of the American College of Radiology mammography accreditation phantom. The methods developed combine correlation approaches, matched filters, and data mining techniques. These methods have been used to analyze radiological images of the accreditation phantom. The classification of structures of interest is based upon reports produced by four trained readers. As previously reported, human observers demonstrate great variation in their analysis due to the subjectivity of human visual inspection. The software tool was trained with three sets of 60 phantom images in order to generate decision trees using the software WEKA (Waikato Environment for Knowledge Analysis). When tested with 240 images during the classification step, the tool correctly classified 88%, 99%, and 98%, of fibers, speck groups and masses, respectively. The variation between the computer classification and human reading was comparable to the variation between human readers. This computerized system not only automates the quality control procedure in mammography, but also decreases the subjectivity in the expert evaluation of the phantom images.

  10. Applying independent component analysis to detect silent speech in magnetic resonance imaging signals.

    Science.gov (United States)

    Abe, Kazuhiro; Takahashi, Toshimitsu; Takikawa, Yoriko; Arai, Hajime; Kitazawa, Shigeru

    2011-10-01

    Independent component analysis (ICA) can be usefully applied to functional imaging studies to evaluate the spatial extent and temporal profile of task-related brain activity. It requires no a priori assumptions about the anatomical areas that are activated or the temporal profile of the activity. We applied spatial ICA to detect a voluntary but hidden response of silent speech. To validate the method against a standard model-based approach, we used the silent speech of a tongue twister as a 'Yes' response to single questions that were delivered at given times. In the first task, we attempted to estimate one number that was chosen by a participant from 10 possibilities. In the second task, we increased the possibilities to 1000. In both tasks, spatial ICA was as effective as the model-based method for determining the number in the subject's mind (80-90% correct per digit), but spatial ICA outperformed the model-based method in terms of time, especially in the 1000-possibility task. In the model-based method, calculation time increased by 30-fold, to 15 h, because of the necessity of testing 1000 possibilities. In contrast, the calculation time for spatial ICA remained as short as 30 min. In addition, spatial ICA detected an unexpected response that occurred by mistake. This advantage was validated in a third task, with 13 500 possibilities, in which participants had the freedom to choose when to make one of four responses. We conclude that spatial ICA is effective for detecting the onset of silent speech, especially when it occurs unexpectedly.

  11. Cerebral cortex classification by conditional random fields applied to intraoperative thermal imaging

    Directory of Open Access Journals (Sweden)

    Hoffmann Nico

    2016-09-01

    Full Text Available Intraoperative thermal neuroimaging is a novel intraoperative imaging technique for the characterization of perfusion disorders, neural activity and other pathological changes of the brain. It bases on the correlation of (sub-cortical metabolism and perfusion with the emitted heat of the cortical surface. In order to minimize required computational resources and prevent unwanted artefacts in subsequent data analysis workflows foreground detection is a important preprocessing technique to differentiate pixels representing the cerebral cortex from background objects. We propose an efficient classification framework that integrates characteristic dynamic thermal behaviour into this classification task to include additional discriminative features. The first stage of our framework consists of learning this representation of characteristic thermal time-frequency behaviour. This representation models latent interconnections in the time-frequency domain that cover specific, yet a priori unknown, thermal properties of the cortex. In a second stage these features are then used to classify each pixel’s state with conditional random fields. We quantitatively evaluate several approaches to learning high-level features and their impact to the overall prediction accuracy. The introduction of high-level features leads to a significant accuracy improvement compared to a baseline classifier.

  12. Hyperspectral imaging techniques applied to the monitoring of wine waste anaerobic digestion process

    Science.gov (United States)

    Serranti, Silvia; Fabbri, Andrea; Bonifazi, Giuseppe

    2012-11-01

    An anaerobic digestion process, finalized to biogas production, is characterized by different steps involving the variation of some chemical and physical parameters related to the presence of specific biomasses as: pH, chemical oxygen demand (COD), volatile solids, nitrate (NO3-) and phosphate (PO3-). A correct process characterization requires a periodical sampling of the organic mixture in the reactor and a further analysis of the samples by traditional chemical-physical methods. Such an approach is discontinuous, time-consuming and expensive. A new analytical approach based on hyperspectral imaging in the NIR field (1000 to 1700 nm) is investigated and critically evaluated, with reference to the monitoring of wine waste anaerobic digestion process. The application of the proposed technique was addressed to identify and demonstrate the correlation existing, in terms of quality and reliability of the results, between "classical" chemical-physical parameters and spectral features of the digestate samples. Good results were obtained, ranging from a R2=0.68 and a RMSECV=12.83 mg/l for nitrate to a R2=0.90 and a RMSECV=5495.16 mg O2/l for COD. The proposed approach seems very useful in setting up innovative control strategies allowing for full, continuous control of the anaerobic digestion process.

  13. [Correlation between basic imaging properties and subjective evaluations of two digital radiographic X-ray systems based on direct-conversion flat panel detector].

    Science.gov (United States)

    Sakaguchi, Taro; Katayama, Reiji; Morishita, Junji; Sakai, Shinji; Kuroki, Hidefumi; Ohkubo, Seiji; Maeda, Takashi; Hayabuchi, Naofumi

    2010-11-20

    The purpose of this study was to examine the correlation between the basic imaging properties of two digital radiographic X-ray systems with a direct conversion flat-panel detector and their image qualities, which were evaluated by the observer in hard copy and soft copy studies. The subjective image quality was evaluated and compared in terms of the low-contrast detectability and image sharpness in the two digital radiographic X-ray systems. We applied the radiographs of a contrast detail phantom to the evaluation of low-contrast detectability and analyzed the contrast detail diagrams. Finally, low-contrast detectability was evaluated by the image quality figure (IQF) calculated from the contrast detail diagrams. Also, the subjective image sharpness of human dry bones of two systems was examined and evaluated by the normalized-rank method. The results indicated that System A tended to provide superior subjective image quality compared to System B in both observer studies. We also found high correlations between IQFs and basic imaging properties, such as the noise power spectrum (NPS) and the noise equivalent quantum (NEQ). In conclusion, the low-contrast detectability of the two digital radiographic X-ray systems with a direct conversion flat-panel detector corresponded to the NPS and the NEQ in both outputs (soft copy and hard copy). On the other hand, the subjective image sharpness of human dry bones was affected by their noise properties.

  14. Optical coherence tomography imaging of psoriasis vulgaris: correlation with histology and disease severity

    DEFF Research Database (Denmark)

    Morsy, Hanan; Kamp, Søren; Thrane, Lars

    2010-01-01

    Epidermal thickness (ET) has been suggested as a surrogate measure of psoriasis severity. Optical coherence tomography (OCT) is a recent imaging technology that provides real-time skin images to a depth of 1.8 mm with a micrometre resolution. OCT may provide an accurate in vivo measure of ET. It is......, therefore, speculated that OCT may be used in the assessment of psoriasis vulgaris. A total of 23 patients with psoriasis vulgaris were systematically evaluated by OCT imaging and skin biopsy during treatment. Biopsies were graded for disease severity, and additional evaluation was done by the physician via...... with a stronger entrance signal, a serrated dermo-epidermal junction was found and a less signal intensity in the dermis as shown in OCT images. ET measured in untreated plaques was thicker reflecting epidermal hyperproliferation and inflammation. The changes were significantly correlated with the biopsy grading...

  15. Magnetic resonance imaging for extramammary Paget's disease: radiological and pathological correlations

    Energy Technology Data Exchange (ETDEWEB)

    Akaike, Gensuke; Nozaki, Taiki; Matsusako, Masaki; Saida, Yukihisa [St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Matsui, Mizuko; Ohtake, Naoyuki [St. Luke' s International Hospital, Department of Plastic Surgery and Reconstructive Surgery, Tokyo (Japan); Eto, Hikaru [St. Luke' s International Hospital, Department of Dermatology, Tokyo (Japan); Suzuki, Koyu [St. Luke' s International Hospital, Department of Pathology, Tokyo (Japan)

    2013-03-15

    Extramammary Paget's disease (EMPD) is a rare cutaneous neoplasm that is thought to represent intraepithelial adenocarcinoma developing in an area rich in apocrine glands. Magnetic resonance imaging (MRI) findings for this disease are not well established. We report three cases of pathologically confirmed EMPD in which MRI was performed before surgery. The lesions were widespread in the epidermis and the dermis. Lesions were sharply well enhanced on gadolinium-enhanced T1-weighted imaging and appeared hyperintense on diffusion-weighted imaging in all cases. Areas with enhancement in depth corresponded well with the pathological lesion. In addition, different malignant legions were found on the same images from MRI in two cases, indicating potential associations with other malignancies. We describe the MRI findings and their pathological correlation. MRI could be useful for preoperative evaluation of disease spread and detection of associated malignancies. (orig.)

  16. Multi-modal contrast of tissue anatomy enables correlative biomarker imaging

    Science.gov (United States)

    Garsha, Karl; Ventura, Franklin; Pestano, Gary; Otter, Michael; Nagy, Dea; Nagle, Ray B.; Roberts, Esteban; Barnes, Michael

    2015-03-01

    Optical imaging techniques are being developed that promise to increase the information content related to specific molecular reporters. Such modalities do not produce contrast in the structural context of the surrounding tissue, making it difficult to reconcile molecular information with morphological context. We report a solution that enables visualization of the tissue morphology on formalin-fixed, paraffin embedded sections prepared for analytical biomarker imaging. Our approach combines modes of transmitted darkfield and fluorescence contrast and computer visualization to produce 2-component image data analogous to the classical hematoxylin and eosin histological stain. An interferometric hyperspectral image capture mode enables measurement of multiplexed biomarkers in annotated anatomic regions. The system enables practical correlative analysis of molecular changes within areas of anatomic pathology.

  17. Imaging of peripheral nerve sheath tumors with pathologic correlation Pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Pilavaki, M.; Chourmouzi, D. E-mail: d.chourmouzi@ips.gr; Kiziridou, A.; Skordalaki, A.; Zarampoukas, T.; Drevelengas, A

    2004-12-01

    Peripheral neurogenic tumors include neurilemoma, neurinoma, and malignant peripheral nerve sheath tumors. All neurogenic tumors share common imaging features. Although differentiation between them is difficult, neurogenic origin can be suggested from their imaging appearances, including fusiform shape, relation to the nerve, 'split-fat' sign, associated muscle atrophy and intrinsic imaging characteristics including 'target sign' as well as from lesion location along a typical nerve distribution. Our purpose is to make an overview of imaging findings of each type of peripheral nerve sheath tumor with emphasis on characteristic signs and correlate with histologic features. Morton's neuroma and intraneural ganglion are also included as tumors of nerve origin.

  18. Estimation of ocean surface currents from maximum cross correlation applied to GOCI geostationary satellite remote sensing data over the Tsushima (Korea) Straits

    Science.gov (United States)

    Warren, M. A.; Quartly, G. D.; Shutler, J. D.; Miller, P. I.; Yoshikawa, Y.

    2016-09-01

    Attempts to automatically estimate surface current velocities from satellite-derived thermal or visible imagery face the limitations of data occlusion due to cloud cover, the complex evolution of features and the degradation of their surface signature. The Geostationary Ocean Color Imager (GOCI) provides a chance to reappraise such techniques due to its multiyear record of hourly high-resolution visible spectrum data. Here we present the results of applying a Maximum Cross Correlation (MCC) technique to GOCI data. Using a combination of simulated and real data we derive suitable processing parameters and examine the robustness of different satellite products, those being water-leaving radiance and chlorophyll concentration. These estimates of surface currents are evaluated using High Frequency (HF) radar systems located in the Tsushima (Korea) Strait. We show the performance of the MCC approach varies depending on the amount of missing data and the presence of strong optical contrasts. Using simulated data it was found that patchy cloud cover occupying 25% of the image pair reduces the number of vectors by 20% compared to using perfect images. Root mean square errors between the MCC and HF radar velocities are of the order of 20 cm s-1. Performance varies depending on the wavelength of the data with the blue-green products out-performing the red and near infra-red products. Application of MCC to GOCI chlorophyll data results in similar performance to radiances in the blue-green bands. The technique has been demonstrated using specific examples of an eddy feature and tidal induced features in the region.

  19. Applying deep learning technology to automatically identify metaphase chromosomes using scanning microscopic images: an initial investigation

    Science.gov (United States)

    Qiu, Yuchen; Lu, Xianglan; Yan, Shiju; Tan, Maxine; Cheng, Samuel; Li, Shibo; Liu, Hong; Zheng, Bin

    2016-03-01

    Automated high throughput scanning microscopy is a fast developing screening technology used in cytogenetic laboratories for the diagnosis of leukemia or other genetic diseases. However, one of the major challenges of using this new technology is how to efficiently detect the analyzable metaphase chromosomes during the scanning process. The purpose of this investigation is to develop a computer aided detection (CAD) scheme based on deep learning technology, which can identify the metaphase chromosomes with high accuracy. The CAD scheme includes an eight layer neural network. The first six layers compose of an automatic feature extraction module, which has an architecture of three convolution-max-pooling layer pairs. The 1st, 2nd and 3rd pair contains 30, 20, 20 feature maps, respectively. The seventh and eighth layers compose of a multiple layer perception (MLP) based classifier, which is used to identify the analyzable metaphase chromosomes. The performance of new CAD scheme was assessed by receiver operation characteristic (ROC) method. A number of 150 regions of interest (ROIs) were selected to test the performance of our new CAD scheme. Each ROI contains either interphase cell or metaphase chromosomes. The results indicate that new scheme is able to achieve an area under the ROC curve (AUC) of 0.886+/-0.043. This investigation demonstrates that applying a deep learning technique may enable to significantly improve the accuracy of the metaphase chromosome detection using a scanning microscopic imaging technology in the future.

  20. An interval prototype classifier based on a parameterized distance applied to breast thermographic images.

    Science.gov (United States)

    Araújo, Marcus C; Souza, Renata M C R; Lima, Rita C F; Filho, Telmo M Silva

    2016-09-15

    Breast cancer is one of the leading causes of death in women. Because of this, thermographic images have received a refocus for diagnosing this cancer type. This work proposes an innovative approach to classify breast abnormalities (malignant, benignant and cyst), employing interval temperature data in order to detect breast cancer. The learning step takes into account the internal variation of the intervals when describing breast abnormalities and uses a way to map these intervals into a space where they can be more easily separated. The method builds class prototypes, and the allocation step is based on a parameterized Mahalanobis distance for interval-valued data. The proposed classifier is applied to a breast thermography dataset from Brazil with 50 patients. We investigate two different scenarios for parameter configuration. The first scenario focuses on the overall misclassification rate and achieves 16 % misclassification rate and 93 % sensitivity to the malignant class. The second scenario maximizes the sensitivity to the malignant class, achieving 100 % sensitivity to this specific class, along with 20 % overall misclassification rate. We compare the performances of our approach and of many methods taken from the literature of interval data classification for the breast thermography task. Results show that our method outperforms competing algorithms.

  1. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    Science.gov (United States)

    Thyagarajan, Nithyanandan; Beardsley, Adam P.; Bowman, Judd D.; Morales, Miguel F.

    2017-05-01

    Modern radio telescopes are favouring densely packed array layouts with large numbers of antennas (NA ≳ 1000). Since the complexity of traditional correlators scales as O(N_A^2), there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (epic), we present the first software demonstration of a generalized direct imaging algorithm, namely the Modular Optimal Frequency Fourier imager. Not only does it bring down the cost for dense layouts to O(N_A log _2N_A) but can also image from irregular layouts and heterogeneous arrays of antennas. epic is highly modular, parallelizable, implemented in object-oriented python, and publicly available. We have verified the images produced to be equivalent to those from traditional techniques to within a precision set by gridding coarseness. We have also validated our implementation on data observed with the Long Wavelength Array (LWA1). We provide a detailed framework for imaging with heterogeneous arrays and show that epic robustly estimates the input sky model for such arrays. Antenna layouts with dense filling factors consisting of a large number of antennas such as LWA, the Square Kilometre Array, Hydrogen Epoch of Reionization Array, and Canadian Hydrogen Intensity Mapping Experiment will gain significant computational advantage by deploying an optimized version of epic. The algorithm is a strong candidate for instruments targeting transient searches of fast radio bursts as well as planetary and exoplanetary phenomena due to the availability of high-speed calibrated time-domain images and low output bandwidth relative to visibility-based systems.

  2. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    Science.gov (United States)

    Thyagarajan, Nithyanandan; Beardsley, Adam P.; Bowman, Judd D.; Morales, Miguel F.

    2017-01-01

    Modern radio telescopes are favouring densely packed array layouts with large numbers of antennas (NA ≳ 1000). Since the complexity of traditional correlators scales as O(N_{A}^2), there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (EPIC), we present the first software demonstration of a generalized direct imaging algorithm, namely, the Modular Optimal Frequency Fourier (MOFF) imager. Not only does it bring down the cost for dense layouts to O(N_{A} log _2N_{A}) but can also image from irregular layouts and heterogeneous arrays of antennas. EPIC is highly modular, parallelizable, implemented in object-oriented Python, and publicly available. We have verified the images produced to be equivalent to those from traditional techniques to within a precision set by gridding coarseness. We have also validated our implementation on data observed with the Long Wavelength Array (LWA1). We provide a detailed framework for imaging with heterogeneous arrays and show that EPIC robustly estimates the input sky model for such arrays. Antenna layouts with dense filling factors consisting of a large number of antennas such as LWA, the Square Kilometre Array, Hydrogen Epoch of Reionization Array, and Canadian Hydrogen Intensity Mapping Experiment will gain significant computational advantage by deploying an optimized version of EPIC. The algorithm is a strong candidate for instruments targeting transient searches of Fast Radio Bursts (FRB) as well as planetary and exoplanetary phenomena due to the availability of high-speed calibrated time-domain images and low output bandwidth relative to visibility-based systems.

  3. Disease activity in Graves' ophthalmopathy: diagnosis with orbital MR imaging and correlation with clinical score.

    Science.gov (United States)

    Tortora, Fabio; Cirillo, Mario; Ferrara, Marco; Belfiore, Maria Paola; Carella, Carlo; Caranci, Ferdinando; Cirillo, Sossio

    2013-10-01

    In Graves' ophthalmopathy (GO) it is important to distinguish acute inflammation at an early stage, responsive to immunosuppressive treatment, from inactive fibrotic end stage disease, unresponsive to the same treatment. The purpose of this study was to identify the most relevant signal intensities on orbital MR imaging with contrast administration both to classify patients according to their clinical activity score (defined by a cut-off value of 3) and to make a prediction of patient's CAS. Such threshold was considered as widely used in literature. Sixteen consecutive patients with a diagnosis of GO in different phases of thyroid disease based on clinical and orbital MR imaging signs, and six normal volunteers were examined. Orbital MR imaging was performed on a 1.5 Tesla MR Unit. MR scans were assessed by an experienced neuroradiologist, blinded to the clinical examinations. We found a statistical correlation between CAS and both STIR and contrast enhanced T1-weighted sequences. There was also a statistically significant correlation between STIR and contrast-enhanced T1 images disclosing the possibility of avoiding the injection of contrast medium. Our study proved that signal intensity values on STIR sequence increase in the inflammatory oedematous phase of disease. We confirmed the correlation between signal intensities on this sequence and CAS, showing an increase in signal intensity proportional to the CAS value. So we validated MRI use to establish the activity phase of disease more sensitively than CAS alone.

  4. Disease Activity in Graves' Ophthalmopathy: Diagnosis with Orbital MR Imaging and Correlation with Clinical Score

    Science.gov (United States)

    Tortora, Fabio; Cirillo, Mario; Ferrara, Marco; Belfiore, Maria Paola; Carella, Carlo; Caranci, Ferdinando; Cirillo, Sossio

    2013-01-01

    Summary In Graves' ophthalmopathy (GO) it is important to distinguish acute inflammation at an early stage, responsive to immunosuppressive treatment, from inactive fibrotic end stage disease, unresponsive to the same treatment. The purpose of this study was to identify the most relevant signal intensities on orbital MR imaging with contrast administration both to classify patients according to their clinical activity score (defined by a cut-off value of 3) and to make a prediction of patient's CAS. Such threshold was considered as widely used in literature. Sixteen consecutive patients with a diagnosis of GO in different phases of thyroid disease based on clinical and orbital MR imaging signs, and six normal volunteers were examined. Orbital MR imaging was performed on a 1.5 Tesla MR Unit. MR scans were assessed by an experienced neuroradiologist, blinded to the clinical examinations. We found a statistical correlation between CAS and both STIR and contrast enhanced T1-weighted sequences. There was also a statistically significant correlation between STIR and contrast-enhanced T1 images disclosing the possibility of avoiding the injection of contrast medium. Our study proved that signal intensity values on STIR sequence increase in the inflammatory oedematous phase of disease. We confirmed the correlation between signal intensities on this sequence and CAS, showing an increase in signal intensity proportional to the CAS value. So we validated MRI use to establish the activity phase of disease more sensitively than CAS alone. PMID:24199816

  5. CT and MR imaging findings of xanthogranulomatous cholecystitis: correlation with pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Shuto, R.; Kiyosue, H.; Komatsu, E.; Matsumoto, S.; Mori, H. [Oita Medical Univ. (Japan). Dept. of Radiology; Kawano, K. [Oita Medical Univ. (Japan). Dept. of First Surgery; Kondo, Y.; Yokoyama, S. [Oita Medical Univ. (Japan). Dept. of First Pathology

    2004-03-01

    The aim of this study was to evaluate CT and MRI findings in xanthogranulomatous cholecystitis (XGC) and to correlate the imaging findings with various pathologic parameters. The study included 13 patients with histopathologically confirmed XGC. The CT (n=13) and MRI (n=5) obtained in these patients were evaluated retrospectively. On CT, low-attenuation areas in the wall of XGC correlated with foam and inflammatory cells or necrosis and/or abscess in XGC. Areas of iso- to slightly high signal intensity on T2-weighted images, showing slight enhancement at early phase and strong enhancement at last phase on dynamic study, corresponded with areas of abundant xanthogranulomas. Areas with very high signal intensity on T2-weighted images without enhancement corresponded with necrosis and/or abscesses. Luminal surface enhancement (LSE) of gallbladder wall represented preservation of the epithelial layer. The early-enhanced areas of the liver bed on dynamic CT and MR images corresponded with accumulation of inflammatory cells and abundant fibrosis. Our results indicate that CT and MRI findings correlate well with the histopathologic findings of XGC.

  6. Intravoxel Incoherent Motion MR Imaging in the Head and Neck: Correlation with Dynamic Contrast-Enhanced MR Imaging and Diffusion-Weighted Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiao Quan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029 (China); Choi, Young Jun; Sung, Yu Sub [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Yoon, Ra Gyoung [Department of Radiology, Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Incheon 22711 (Korea, Republic of); Jang, Seung Won; Park, Ji Eun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Heo, Young Jin [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan 47392 (Korea, Republic of); Baek, Jung Hwan; Lee, Jeong Hyun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

    2016-11-01

    To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D{sup *}), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D{sup *} and model-free parameters from the DCE-MRI (wash-in, T{sub max}, E{sub max}, initial AUC{sub 60}, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D{sup *} and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p < 0.001, r = 0.980) and muscles (p = 0.013, r = 0.542), despite its significantly higher value than D. The difference between ADC and D showed significant correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D{sup *} (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

  7. Intravoxel incoehrent motion MR imaging in the head and neck: Correlation with dynamic contrast-enhanced MR imaging and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiao Quan; Choi, Young Jun; Sung, Yu Sub; Jang, Seung Won; Park, Ji Eun; Heo, Young Jin; Beak, Jung Hwan; Lee, Jeong Hyun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Yoon, Ra Gyoung [Dept. of Radiology, Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Incheon (Korea, Republic of)

    2016-09-15

    To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D{sup *}), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D{sup *} and model-free parameters from the DCE-MRI (wash-in, T{sub max}, E{sub max}, initial AUC{sub 60}, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. No correlation was found between f or D{sup *} and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p < 0.001, r = 0.980) and muscles (p = 0.013, r = 0.542), despite its significantly higher value than D. The difference between ADC and D showed significant correlation with f values in the tumors (p = 0.017, r = 0.528) and muscles (p = 0.003, r = 0.630), but no correlation with D{sup *} (p > 0.05, respectively). Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

  8. Imaging diagnosis in relapsing polychondritis and correlation with clinical and serological data

    Energy Technology Data Exchange (ETDEWEB)

    Thaiss, W.M.; Nikolaou, K.; Horger, M. [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Tuebingen (Germany); Spengler, W.; Xenitidis, T.; Henes, J. [Eberhard Karls University, Department of Internal Medicine II, Tuebingen (Germany); Spira, D. [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Tuebingen (Germany); University Medical Center Heidelberg, Diagnostic and Interventional Radiology, Heidelberg (Germany)

    2016-03-15

    We hypothesize that imaging findings from CT and MRI correlate better with clinical markers for assessment of disease activity in patients with the rare relapsing polychondritis (RPC) than with serological inflammatory markers. Retrospective database search at our institution identified 28 patients (13 females; age 49.0 years ± 15.0 SD) with RP between September 2004 and March 2014. Institutional review board approval was obtained for this retrospective data analysis. All patients had clinically proven RPC with at least two episodes of active disease. Of those, 18 patients were examined with CT- and MRI and presented all morphologic features of RPC like bronchial/laryngeal/auricular cartilage thickness, contrast enhancement, increased T2-signal intensity. Imaging data was subsequently correlated with corresponding clinical symptoms like fever, dyspnea, stridor, uveitis, pain, hearing impairment as well as with acute-phase-inflammatory parameters like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The clinical parameters were in good agreement with imaging findings and clinical symptoms such as tracheal wall thickening and dyspnea (r =0.65 p = 0.05), joint synovitis on MRI and a higher McAdam score (r = 0.84 p < 0.001). No correlations were found between inflammatory laboratory markers, imaging findings and clinical features. Imaging diagnosis in RPC using CT and/or MRI delivers information about the degree of disease activity that correlates better with clinical features than unspecific inflammatory laboratory markers. Additionally, clinically unapparent cartilage involvement can be assessed adding value to the clinical diagnosis and therapy planning in this rare disease. (orig.)

  9. Partial correlation analyses of global diffusion tensor imaging-derived metrics in glioblastoma multiforme: Pilot study

    Institute of Scientific and Technical Information of China (English)

    David; Cortez-Conradis; Camilo; Rios; Sergio; Moreno-Jimenez; Ernesto; Roldan-Valadez; Ernesto; Roldan-Valadez

    2015-01-01

    AIM: To determine existing correlates among diffusion tensor imaging(DTI)-derived metrics in healthy brains and brains with glioblastoma multiforme(GBM). METHODS: Case-control study using DTI data from brain magnetic resonance imaging of 34 controls(mean, 41.47; SD, ± 21.94 years; range, 21-80 years) and 27 patients with GBM(mean, SD; 48.41 ± 15.18 years; range, 18-78 years). Image postprocessing using FSL software calculated eleven tensor metrics: fractional(FA) and relative anisotropy; pure isotropic(p) and anisotropic diffusions(q), total magnitude of diffusion(L); linear(Cl), planar(Cp) and spherical tensors(Cs); mean(MD), axial(AD) and radial diffusivities(RD). Partial correlation analyses(controlling the effect of ageand gender) and multivariate Mancova were performed.RESULTS: There was a normal distribution for all metrics. Comparing healthy brains vs brains with GBM, there were significant very strong bivariate correlations only depicted in GBM: [FA?Cl(+)], [FA?q(+)], [p?AD(+)], [AD?MD(+)], and [MD?RD(+)]. Among 56 pairs of bivariate correlations, only seven were significantly different. The diagnosis variable depicted a main effect [F-value(11, 23) = 11.842, P ≤ 0.001], with partial eta squared = 0.850, meaning a large effect size; age showed a similar result. The age also had a significant influence as a covariate [F(11, 23) = 10.523, P < 0.001], with a large effect size(partial eta squared = 0.834).CONCLUSION: DTI-derived metrics depict significant differences between healthy brains and brains with GBM, with specific magnitudes and correlations. This study provides reference data and makes a contribution to decrease the underlying empiricism in the use of DTI parameters in brain imaging.

  10. Non-uniform object counting method in large-format pyramid images applied to CD31 vessel counting in whole-mount digital pathology sections

    Science.gov (United States)

    Murray, Mayan; Hill, Melissa L.; Liu, Kela; Mainprize, James G.; Yaffe, Martin J.

    2016-03-01

    Whole-mount pathology imaging has the potential to revolutionize clinical practice by preserving context lost when tissue is cut to fit onto conventional slides. Whole-mount digital images are very large, ranging from 4GB to greater than 50GB, making concurrent processing infeasible. Block-processing is a method commonly used to divide the image into smaller blocks and process them individually. This approach is useful for certain tasks, but leads to over-counting objects located on the seams between blocks. This issue is exaggerated as the block size decreases. In this work we apply a novel technique to enumerate vessels, a clinical task that would benefit from automation in whole-mount images. Whole-mount sections of rabbit VX2 tumors were digitized. Color thresholding was used to segment the brown CD31- DAB stained vessels. This vessel enumeration was applied to the entire whole-mount image in two distinct phases of block-processing. The first (whole-processing) phase used a basic grid and only counted objects that did not intersect the block's borders. The second (seam-processing) phase used a shifted grid to ensure all blocks captured the block-seam regions from the original grid. Only objects touching this seam-intersection were counted. For validation, segmented vessels were randomly embedded into a whole-mount image. The technique was tested on the image using 24 different block-widths. Results indicated that the error reaches a minimum at a block-width equal to the maximum vessel length, with no improvement as the block-width increases further. Object-density maps showed very good correlation between the vessel-dense regions and the pathologist outlined tumor regions.

  11. A Statistical Definition of Image Resolution Based on the Correlation of Pixels

    CERN Document Server

    Zhou, Jian-Feng

    2015-01-01

    Resolution, usually defined by the Rayleigh criterion or the Full Width at Half Maximum of a Point Spread Function, is a basic property of an image. Here, we present a new statistical definition of image resolution based on the cross-correlation properties of the pixels in an image. It is shown that the new definition of image resolution depends not only on the PSF of an imaging device, but also on the signal-to-noise ratio of the data and on the structures of an object. In an image, the resolution does not have to be uniform. Our new definition is also suitable for the interpretation of the result of a deconvolution. We illustrate this, in this paper, with a Wiener deconvolution. It is found that weak structures can be extracted from low signal-to-noise ratio data, but with low resolution; a high-resolution image was obtained from high signal-to-noise ratio data after a Wiener deconvolution. The new definition can also be used to compare various deconvolution algorithms on their processing effects, such as r...

  12. Three-dimensional correlation of MR images to muscle tissue response for interventional MRI thermal ablation

    Science.gov (United States)

    Breen, Michael S.; Lazebnik, Roee S.; Lewin, Jonathan S.; Wilson, David L.

    2003-05-01

    Solid tumors and other pathologies are being treated using radio-frequency (RF) ablation under interventional magnetic resonance imaging (iMRI) guidance. In animal experiments, we are investigating the ability of MR to monitor ablation treatments by comparing MR images of thermal lesions to histologically assayed cellular damage. We developed a new methodology using three-dimensional registration for making spatial correlations. A low-field, open MRI system was used to guide an ablation probe into the thigh muscle of 10 rabbits and acquire MR volumes post ablation. After the in vivo MR and histology images were aligned with a registration accuracy of 1.32 +/- 0.39 mm (mean +/- SD), a boundary of necrosis identified in histology images was compared with manually segmented boundaries of the elliptical hyperintense region in MR images. For 14 MR images, we determined that the outer boundary of the hyperintense region in MR closely corresponds to the region of cell death, with a mean absolute distance between boundaries of 0.97 mm. Since this distance may be less than our ability to measure such differences, boundaries may match perfectly. This is good evidence that MR lesion images can localize the region of cell death during RF ablation treatments.

  13. MR imaging findings of painful type II accessory navicular bone: correlation with surgical and pathologic studies

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Sun; Lee, Kyung Tai; Kim, Eun Kyung [Eulji Hospital, Eulji University School of Medicine, Daejeon (Korea, Republic of); Kang, Heung Sik [Seoul National University Bundang Hospital, Seoul (Korea, Republic of)

    2004-12-15

    To evaluate the MR imaging findings of painful type II accessory navicular bone and to correlate these with the surgical and pathologic findings. The MR images of 17 patients with medial foot pain and surgically proven type II accessory navicular abnormalities were reviewed. The changes of signal intensity in the accessory navicular, synchondrosis and adjacent soft tissue, the presence of synchondrosis widening, and posterior tibial tendon (PTT) pathology on the T1-weighted and fat-suppressed T2-weighted images were analyzed. The MR imaging findings were compared with the surgical and pathologic findings. The fat-suppressed T2-weighted images showed high signal intensity in the accessory navicular bones and synchondroses in all patients, and in the soft tissue in 11 (64.7%) of the 17 patients, as well as synchondrosis widening in 3 (17.6%) of the 17 patients. The MR images showed tendon pathology in 12 (75%) of the 16 patients with PTT dysfunction at surgery. The pathologic findings of 16 surgical specimens included areas of osteonecrosis with granulomatous inflammation, fibrosis and destruction of the cartilage cap. The MR imaging findings of painful type II accessory navicular bone are a persistent edema pattern in the accessory navicular bone and within the synchondrosis, indicating osteonecrosis, inflammation and destruction of the cartilage cap. Posterior tibial tendon dysfunction was clinically evident in most patients.

  14. Technical Note: Method to correlate whole-specimen histopathology of radical prostatectomy with diagnostic MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, Deirdre M., E-mail: d.mcgrath@sheffield.ac.uk; Lee, Jenny; Foltz, Warren D. [Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Samavati, Navid [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9 (Canada); Jewett, Michael A. S. [Departments of Surgery (Urology) and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Kwast, Theo van der [Pathology Department, University Health Network, Toronto, Ontario M5G 2C4 (Canada); Chung, Peter [Radiation Medicine Program, Princess Margaret Hospital, University Health Network and the University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Ménard, Cynthia [Radiation Medicine Program, Princess Margaret Hospital, University Health Network and the University of Toronto, Toronto, Ontario M5G 2M9, Canada and Centre Hospitalier de l’Université de Montréal, 1058 Rue Saint-Denis, Montréal, Québec H2X 3J4 (Canada); Brock, Kristy K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48108 (United States)

    2016-03-15

    Purpose: Validation of MRI-guided tumor boundary delineation for targeted prostate cancer therapy is achieved via correlation with gold-standard histopathology of radical prostatectomy specimens. Challenges to accurate correlation include matching the pathology sectioning plane with the in vivo imaging slice plane and correction for the deformation that occurs between in vivo imaging and histology. A methodology is presented for matching of the histological sectioning angle and position to the in vivo imaging slices. Methods: Patients (n = 4) with biochemical failure following external beam radiotherapy underwent diagnostic MRI to confirm localized recurrence of prostate cancer, followed by salvage radical prostatectomy. High-resolution 3-D MRI of the ex vivo specimens was acquired to determine the pathology sectioning angle that best matched the in vivo imaging slice plane, using matching anatomical features and implanted fiducials. A novel sectioning device was developed to guide sectioning at the correct angle, and to assist the insertion of reference dye marks to aid in histopathology reconstruction. Results: The percentage difference in the positioning of the urethra in the ex vivo pathology sections compared to the positioning in in vivo images was reduced from 34% to 7% through slicing at the best match angle. Reference dye marks were generated, which were visible in ex vivo imaging, in the tissue sections before and after processing, and in histology sections. Conclusions: The method achieved an almost fivefold reduction in the slice-matching error and is readily implementable in combination with standard MRI technology. The technique will be employed to generate datasets for correlation of whole-specimen prostate histopathology with in vivo diagnostic MRI using 3-D deformable registration, allowing assessment of the sensitivity and specificity of MRI parameters for prostate cancer. Although developed specifically for prostate, the method is readily

  15. Triceps brachii tendon: anatomic-MR imaging study in cadavers with histologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Belentani, Clarissa [University of California, Department of Radiology, San Diego, CA (United States); Pastore, Daniel; Wangwinyuvirat, Mani; Dirim, Berna; Trudell, Debra J.; Resnick, Donald [University of California, Department of Radiology, San Diego, CA (United States); University of California, VA Medical Center, San Diego, CA (United States); Haghighi, Parviz [University of California, VA Medical Center, San Diego, CA (United States); University of California, Department of Histology, San Diego (United States)

    2009-02-15

    The purpose of this cadaveric study was to describe the normal MR anatomy of the triceps brachii tendon (TBT) insertion, to correlate the findings with those seen in anatomic sections and histopathologic analysis, and to review triceps tendon injuries. Twelve cadaveric elbows were used according to institution guidelines. T1-weighted spin-echo MR images were acquired in three planes. Findings on MR imaging were correlated with those derived from anatomic and histologic study. On MR images, the TBT had a bipartite appearance as it inserted on olecranon in all specimens. The insertion of the medial head was deeper than that of the long and lateral heads and was mainly muscular at its insertion, with a small amount of the tendon blending with the muscle distally, necessitating histologic analysis to determine if there was tendon blending with the muscle at the site of insertion and if the medial head inserted together with the common tendon or as a single unit. At histopathologic analysis, the three heads of the triceps tendon had a common insertion on the olecranon. The bipartite aspect of the tendon that was identified in the MR images was not seen by histologic study, indicating that there was a union of the medial and common tendons just before they inserted into bone. TBT has a bipartite appearance on MR images and inserts on olecranon as a single unit. (orig.)

  16. Correlative imaging of fluorescent proteins in resin-embedded plant material.

    Science.gov (United States)

    Bell, Karen; Mitchell, Steve; Paultre, Danae; Posch, Markus; Oparka, Karl

    2013-04-01

    Fluorescent proteins (FPs) were developed for live-cell imaging and have revolutionized cell biology. However, not all plant tissues are accessible to live imaging using confocal microscopy, necessitating alternative approaches for protein localization. An example is the phloem, a tissue embedded deep within plant organs and sensitive to damage. To facilitate accurate localization of FPs within recalcitrant tissues, we developed a simple method for retaining FPs after resin embedding. This method is based on low-temperature fixation and dehydration, followed by embedding in London Resin White, and avoids the need for cryosections. We show that a palette of FPs can be localized in plant tissues while retaining good structural cell preservation, and that the polymerized block face can be counterstained with cell wall probes. Using this method we have been able to image green fluorescent protein-labeled plasmodesmata to a depth of more than 40 μm beneath the resin surface. Using correlative light and electron microscopy of the phloem, we were able to locate the same FP-labeled sieve elements in semithin and ultrathin sections. Sections were amenable to antibody labeling, and allowed a combination of confocal and superresolution imaging (three-dimensional-structured illumination microscopy) on the same cells. These correlative imaging methods should find several uses in plant cell biology.

  17. A three-phase time-correlation image sensor using pinned photodiode active pixels

    Science.gov (United States)

    Han, Sangman; Iwahori, Tomohiro; Sawada, Tomonari; Kawahito, Shoji; Ando, Shigeru

    2010-01-01

    A time correlation (TC) image sensor is a device that produces 3-phase time-correlated signals between the incident light intensity and three reference signals. A conventional implementation of the TC image sensor using a standard CMOS technology works at low frequency and with low sensitivity. In order to achieve higher modulation frequency and high sensitivity, the TC image sensor with a dual potential structure using a pinned diode is proposed. The dual potential structure is created by changing the impurity doping concentration in the two different potential regions. In this structure, high-frequency modulation can be achieved, while maintaining a sufficient light receiving area. A prototype TC image sensor with 366×390pixels is implemented with 0.18-μm 1P4M CMOS image sensor technology. Each pixel with the size of 12μm×12μm has one pinned photodiode with the dual potential structure, 12 transistors and 3capacitors to implement three-parallel-output active pixel circuits. A fundamental operation of the implemented TC sensor is demonstrated.

  18. Discrimination and identification of RDX/PETN explosives by chemometrics applied to terahertz time-domain spectral imaging

    Science.gov (United States)

    Bou-Sleiman, J.; Perraud, J.-B.; Bousquet, B.; Guillet, J.-P.; Palka, N.; Mounaix, P.

    2015-10-01

    Detection of explosives has always been a priority for homeland security. Jointly, terahertz spectroscopy and imaging are emerging and promising candidates as contactless and safe systems. In this work, we treated data resulting from hyperspectral imaging obtained by THz-time domain spectroscopy, with chemometric tools. We found efficient identification and sorting of targeted explosives in the case of pure and mixture samples. In this aim, we applied to images Principal Component Analysis (PCA) to discriminate between RDX, PETN and mixtures of the two materials, using the absorbance as the key-parameter. Then we applied Partial Least Squares-Discriminant Analysis (PLS-DA) to each pixel of the hyperspectral images to sort the explosives into different classes. The results clearly show successful identification and categorization of the explosives under study.

  19. Data Mining Based Skin Pixel Detection Applied On Human Images: A Study Paper

    Directory of Open Access Journals (Sweden)

    Gagandeep Kaur

    2014-07-01

    Full Text Available Skin segmentation is the process of the identifying the skin pixels in a image in a particular color model and dividing the images into skin and non-skin pixels. It is the process of find the particular skin of the image or video in a color model. Finding the regions of the images in human images to say these pixel regions are part of the image or videos is typically a preprocessing step in skin detection in computer vision, face detection or multi-view face detection. Skin pixel detection model converts the images into appropriate format in a color space and then classification process is being used for labeling of the skin and non-skin pixels. A skin classifier identifies the boundary of the skin image in a skin color model based on the training dataset. Here in this paper, we present the survey of the skin pixel segmentation using the learning algorithms.

  20. Correlation of diffusion tensor imaging parameters with neural status in Pott’s spine

    Directory of Open Access Journals (Sweden)

    Jain Nikhil

    2016-01-01

    Full Text Available Introduction: Diffusion tensor imaging (DTI has been used in cervical trauma and spondylotic myelopathy, and it has been found to correlate with neural deficit and prognosticate neural recovery. Such a correlation has not been studied in Pott’s spine with paraplegia. Hence, this prospective study has been used to find correlation of DTI parameters with neural deficit in these patients. Methods: Thirty-four patients of spinal TB were enrolled and DTI was performed before the start of treatment and after six months. Fractional anisotropy (FA, Mean diffusivity (MD, and Tractography were studied. Neurological deficit was graded by the Jain and Sinha scoring. Changes in FA and MD at and below the site of lesion (SOL were compared to above the SOL (control using the unpaired t-test. Pre-treatment and post-treatment values were also compared using the paired t-test. Correlation of DTI parameters with neurological score was done by Pearson’s correlation. Subjective assessment of Tractography images was done. Results: Mean average FA was not significantly decreased at the SOL in patients with paraplegia as compared to control. After six months of treatment, a significant decrease (p = 0.02 in mean average FA at the SOL compared to pre-treatment was seen. Moderate positive correlation (r = 0.49 between mean average FA and neural score after six months of treatment was found. Tractography images were not consistent with severity of paraplegia. Conclusion: Unlike spondylotic myelopathy and trauma, epidural collection and its organized inflammatory tissue in Pott’s spine precludes accurate assessment of diffusion characteristics of the compressed cord.

  1. Image patch analysis of sunspots and active regions. I. Intrinsic dimension and correlation analysis

    Science.gov (United States)

    Moon, Kevin R.; Li, Jimmy J.; Delouille, Véronique; De Visscher, Ruben; Watson, Fraser; Hero, Alfred O.

    2016-01-01

    Context. The flare productivity of an active region is observed to be related to its spatial complexity. Mount Wilson or McIntosh sunspot classifications measure such complexity but in a categorical way, and may therefore not use all the information present in the observations. Moreover, such categorical schemes hinder a systematic study of an active region's evolution for example. Aims: We propose fine-scale quantitative descriptors for an active region's complexity and relate them to the Mount Wilson classification. We analyze the local correlation structure within continuum and magnetogram data, as well as the cross-correlation between continuum and magnetogram data. Methods: We compute the intrinsic dimension, partial correlation, and canonical correlation analysis (CCA) of image patches of continuum and magnetogram active region images taken from the SOHO-MDI instrument. We use masks of sunspots derived from continuum as well as larger masks of magnetic active regions derived from magnetogram to analyze separately the core part of an active region from its surrounding part. Results: We find relationships between the complexity of an active region as measured by its Mount Wilson classification and the intrinsic dimension of its image patches. Partial correlation patterns exhibit approximately a third-order Markov structure. CCA reveals different patterns of correlation between continuum and magnetogram within the sunspots and in the region surrounding the sunspots. Conclusions: Intrinsic dimension has the potential to distinguish simple from complex active regions. These results also pave the way for patch-based dictionary learning with a view toward automatic clustering of active regions.

  2. Adaptive FPGA NoC-based Architecture for Multispectral Image Correlation

    CERN Document Server

    Zhang, Linlin; Fresse, Virginie; Fischer, Viktor

    2009-01-01

    An adaptive FPGA architecture based on the NoC (Network-on-Chip) approach is used for the multispectral image correlation. This architecture must contain several distance algorithms depending on the characteristics of spectral images and the precision of the authentication. The analysis of distance algorithms is required which bases on the algorithmic complexity, result precision, execution time and the adaptability of the implementation. This paper presents the comparison of these distance computation algorithms on one spectral database. The result of a RGB algorithm implementation was discussed.

  3. Symptomatic resolution of spinal osteoid osteoma with conservative management: imaging correlation

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, Prakash [The Royal National Orthopaedic Hospital, Spinal Surgery, London (United Kingdom); The Whitehouse, Enfield, Middlesex (United Kingdom); Harish, S. [The Royal National Orthopaedic Hospital, Radiology, London (United Kingdom); Nnadi, Colin; Noordeen, Hilali [The Royal National Orthopaedic Hospital, Spinal Surgery, London (United Kingdom); Saifuddin, Asif [The Royal National Orthopaedic Hospital, Department of Imaging, London (United Kingdom)

    2007-06-15

    A 10-year-old girl presented with a history of painful scoliosis. Imaging performed, including computed tomography (CT) and magnetic resonance imaging (MRI), demonstrated a lesion with radiological features consistent with an osteoid osteoma (OO) of the 6th thoracic vertebra. The patient was treated conservatively with non-steroidal anti-inflammatory drugs (NSAIDs). Over eight months of clinical and radiological surveillance, she became entirely asymptomatic and demonstrated complete resolution of the scoliotic curve. The CT and MRI features of the osteoid osteoma during the period of surveillance are presented and are correlated with the corresponding clinical features. (orig.)

  4. Morphological characterization of keratoconus-affected human corneas by SHG imaging and correlation analysis

    Science.gov (United States)

    Mercatelli, R.; Ratto, F.; Tatini, F.; Rossi, F.; Menabuoni, L.; Nicoletti, R.; Pini, R.; Pavone, Frederick; Cicchi, R.

    2016-03-01

    Keratoconus is an ophthalmic disease in which the cornea acquires an abnormal conical shape that prevents the correct focusing on the retina, causing visual impairment. The late diagnosis of keratoconus is among the principal causes of corneal transplantation surgery. In this study, we characterize the morphology of keratoconic corneas by means of the correlation of SHG images, finding that keratoconus can be diagnosed by analyzing the inclination of lamellae below Bowman's membrane. In addition, imaging performed with both sagittal and "en face" geometry demonstrated that this morphological features can be highlighted both ex vivo and in vivo.

  5. Comparison Study of Different Lossy Compression Techniques Applied on Digital Mammogram Images

    Directory of Open Access Journals (Sweden)

    Ayman AbuBaker

    2016-12-01

    Full Text Available The huge growth of the usage of internet increases the need to transfer and save multimedia files. Mammogram images are part of these files that have large image size with high resolution. The compression of these images is used to reduce the size of the files without degrading the quality especially the suspicious regions in the mammogram images. Reduction of the size of these images gives more chance to store more images and minimize the cost of transmission in the case of exchanging information between radiologists. Many techniques exists in the literature to solve the loss of information in images. In this paper, two types of compression transformations are used which are Singular Value Decomposition (SVD that transforms the image into series of Eigen vectors that depends on the dimensions of the image and Discrete Cosine Transform (DCT that covert the image from spatial domain into frequency domain. In this paper, the Computer Aided Diagnosis (CAD system is implemented to evaluate the microcalcification appearance in mammogram images after using the two transformation compressions. The performance of both transformations SVD and DCT is subjectively compared by a radiologist. As a result, the DCT algorithm can effectively reduce the size of the mammogram images by 65% with high quality microcalcification appearance regions.

  6. AN ADVANCED COARSE-FINE SEARCH APPROACH FOR DIGITAL IMAGE CORRELATION APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Samo Simončič

    2016-04-01

    Full Text Available The paper presents a newly developed fine search algorithm used in the application of digital correlation. In order to evaluate its performance a special purpose application was developed using C# programming language. The algorithm was then tested on a pre-prepared set of the computer generated speckled images. It turned out to be much faster than the conventional fine search algorithm. Consequently, it is a major step forward in a never ending quest for a fast digital correlation execution with sub pixel accuracy.

  7. High Resolution Pulse Compression Imaging Using Super Resolution FM-Chirp Correlation Method (SCM)

    Science.gov (United States)

    Fujiwara, M.; Okubo, K.; Tagawa, N.

    This study addresses the issue of the super-resolution pulse compression technique (PCT) for ultrasound imaging. Time resolution of multiple ultrasonic echoes using the FM-Chirp PCT is limited by the bandwidth of the sweep-frequency. That is, the resolution depends on the sharpness of auto-correlation function. We propose the Super resolution FM-Chirp correlation Method (SCM) and evaluate its performance. This method is based on the multiple signal classification (MUSIC) algorithm. Our simulations were made for the model assuming multiple signals reflected from some scatterers. We confirmed that SCM detects time delay of complicated reflected signals successfully with high resolution.

  8. White matter correlates of cognitive domains in normal aging with diffusion tensor imaging

    Directory of Open Access Journals (Sweden)

    Efrat eSasson

    2013-03-01

    Full Text Available The ability to perform complex as well as simple cognitive tasks engages a network of brain regions that is mediated by the white matter fiber bundles connecting them. Different cognitive tasks employ distinctive white matter fiber bundles. The temporal lobe and its projections subserve a variety of key functions known to deteriorate during aging. In a cohort of 52 healthy subjects (ages 25-82 years, we performed voxel-wise regression analysis correlating performance in higher-order cognitive domains (executive function, information processing speed, and memory with white matter integrity, as measured by diffusion tensor imaging (DTI fiber tracking in the temporal lobe projections (uncinate fasciculus (UF, fornix, cingulum, inferior longitudinal fasciculus (ILF, and superior longitudinal fasciculus (SLF. The fiber tracts were spatially registered and statistical parametric maps were produced to spatially localize the significant correlations. Results showed that performance in the executive function domain is correlated with DTI parameters in the left SLF and right UF; performance in the information processing speed domain is correlated with fractional anisotropy (FA in the left cingulum, left fornix, right and left ILF and SLF; and the memory domain shows significant correlations with DTI parameters in the right fornix, right cingulum, left ILF, left SLF and right UF. These findings suggest that DTI tractography enables anatomical definition of region of interest for correlation of behavioral parameters with diffusion indices, and functionality can be correlated with white matter integrity.

  9. Knee joint examinations by magnetic resonance imaging: The correlation of pathology, age, and sex

    Directory of Open Access Journals (Sweden)

    Serhat Avcu

    2010-01-01

    Full Text Available Aims: The aim of our study was to investigate the incidence and coexistence of multiple knee joint pathologies and the distribution of knee joint pathologies according to age and sex. Patients and Methods: A retrospective analysis was performed using the clinical data of patients evaluated with magnetic resonance imaging (MRI of the knee joint. Data from 308 patients examined between August 2002 and July 2003 were included into this study. A Pearson correlation analysis was performed to examine the relationship between the pathological findings and the age and sex of the patients. Results: The ages of the patients ranged between 1 and 74 years (mean: 43.3 years. Age was significantly correlated with meniscal degeneration and tears, medial collateral ligament degeneration, parameniscal cyst, and chondromalacia patellae. There was a significant correlation between male gender and anterior cruciate ligament injury. Meniscal injury was significantly correlated with bursitis, as well as medial collateral ligament injury. Bone bruise was significantly correlated with medial collateral ligament injury, lateral collateral ligament injury, Baker′s cyst, and anterior cruciate ligament injury. Chondromalacia patellae was significantly correlated with anterior cruciate ligament injury, patellae alta, and osteochondral lesion. Bursitis (in 53.2% of the patients followed by grade-II meniscal degeneration (in 43% of the patients were the most common knee pathologies observed by MRI. Conclusions: MRI findings of select knee pathologies are significantly correlated with each other and the age and sex of the patient.

  10. Knee joint examinations by magnetic resonance imaging: The correlation of pathology, age, and sex

    Directory of Open Access Journals (Sweden)

    Serhat Avcu

    2010-04-01

    Full Text Available Aims: The aim of our study was to investigate the incidence and coexistence of multiple knee joint pathologies and the distribution of knee joint pathologies according to age and sex. Patients and Methods: A retrospective analysis was performed using the clinical data of patients evaluated with magnetic resonance imaging (MRI of the knee joint. Data from 308 patients examined between August 2002 and July 2003 were included into this study. A Pearson correlation analysis was performed to examine the relationship between the pathological findings and the age and sex of the patients. Results: The ages of the patients ranged between 1 and 74 years (mean: 43.3 years. Age was significantly correlated with meniscal degeneration and tears, medial collateral ligament degeneration, parameniscal cyst, and chondromalacia patellae. There was a significant correlation between male gender and anterior cruciate ligament injury. Meniscal injury was significantly correlated with bursitis, as well as medial collateral ligament injury. Bone bruise was significantly correlated with medial collateral ligament injury, lateral collateral ligament injury, Baker’s cyst, and anterior cruciate ligament injury. Chondromalacia patellae was significantly correlated with anterior cruciate ligament injury, patellae alta, and osteochondral lesion. Bursitis (in 53.2% of the patients followed by grade-II meniscal degeneration (in 43% of the patients were the most common knee pathologies observed by MRI. Conclusions: MRI findings of select knee pathologies are significantly correlated with each other and the age and sex of the patient.

  11. Noninvasive measurement of burn wound depth applying infrared thermal imaging (Conference Presentation)

    Science.gov (United States)

    Jaspers, Mariëlle E.; Maltha, Ilse M.; Klaessens, John H.; Vet, Henrica C.; Verdaasdonk, Rudolf M.; Zuijlen, Paul P.

    2016-02-01

    In burn wounds early discrimination between the different depths plays an important role in the treatment strategy. The remaining vasculature in the wound determines its healing potential. Non-invasive measurement tools that can identify the vascularization are therefore considered to be of high diagnostic importance. Thermography is a non-invasive technique that can accurately measure the temperature distribution over a large skin or tissue area, the temperature is a measure of the perfusion of that area. The aim of this study was to investigate the clinimetric properties (i.e. reliability and validity) of thermography for measuring burn wound depth. In a cross-sectional study with 50 burn wounds of 35 patients, the inter-observer reliability and the validity between thermography and Laser Doppler Imaging were studied. With ROC curve analyses the ΔT cut-off point for different burn wound depths were determined. The inter-observer reliability, expressed by an intra-class correlation coefficient of 0.99, was found to be excellent. In terms of validity, a ΔT cut-off point of 0.96°C (sensitivity 71%; specificity 79%) differentiates between a superficial partial-thickness and deep partial-thickness burn. A ΔT cut-off point of -0.80°C (sensitivity 70%; specificity 74%) could differentiate between a deep partial-thickness and a full-thickness burn wound. This study demonstrates that thermography is a reliable method in the assessment of burn wound depths. In addition, thermography was reasonably able to discriminate among different burn wound depths, indicating its potential use as a diagnostic tool in clinical burn practice.

  12. Distal insertions of the semimembranosus tendon: MR imaging with anatomic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Maeseneer, Michel de [Universitair Ziekenhuis Brussel, Department of Radiology, Jette, Brussels (Belgium); Vrije Universiteit Brussel, Department of Experimental Anatomy, Brussels (Belgium); Shahabpour, Maryam; Milants, Annemieke; Ridder, Filip de; Mey, Johan de [Universitair Ziekenhuis Brussel, Department of Radiology, Jette, Brussels (Belgium); Lenchik, Leon [Wake Forest University, Department of Radiology, Winston-Salem, NC (United States); Cattrysse, Erik [Vrije Universiteit Brussel, Department of Experimental Anatomy, Brussels (Belgium)

    2014-06-15

    The purpose of this study is to investigate the distal insertions of the semimembranosus tendon with MR imaging, correlated with findings in cadavers. Four fresh cadaveric specimens were studied with 3-T MR imaging. Sequences included proton density (PD) sequences (TE, 13; TR, 4957; FOV, 170 x 170; matrix, 424 x 413; NA, 2; slice thickness, 2.5 mm) in the axial, coronal, and sagittal planes and 3D fast field echo (FFE) sequences (TR 9.4; TE 6.9; FOV, 159 x 105; matrix, 200 x 211; NA, 2; slice thickness, 0.57 mm). One specimen was dissected and three specimens were sectioned with a bandsaw in the axial, coronal, and sagittal plane. The sections were photographed and correlated with MR images. To standardize the analysis, the semimembranosus muscle and tendon were assessed at seven levels for the axial sections, and at three levels for the coronal and sagittal sections. Anatomic dissection revealed six insertions of the distal semimembranosus tendon: direct arm, anterior arm, posterior oblique ligament extension, oblique popliteal ligament extension, distal tibial expansion (popliteus aponeurosis), and meniscal arm. Axial MR images showed five of six insertions: direct arm, anterior arm, oblique popliteal ligament extension, posterior oblique ligament extension, and distal tibial expansion. Sagittal MR images showed four of six insertions: direct arm, anterior arm, oblique popliteal ligament arm, and distal tibial expansion. Sagittal MR images were ideal for showing the direct arm insertion, but were less optimal than the axial images for showing the other insertions. The anterior arm was seen but volume averaging was present with the gracilis tendon. Coronal MR images optimally revealed the anterior arm, although magic angle artifact was present at its posterior aspect. The common semimembranosus tendon and meniscal arm were also well depicted. The division in anterior arm, direct arm, and oblique popliteal ligament arm was poorly seen on coronal images due to

  13. Optimized acquisition scheme for multi-projection correlation imaging of breast cancer

    Science.gov (United States)

    Chawla, Amarpreet S.; Samei, Ehsan; Saunders, Robert S.; Lo, Joseph Y.; Singh, Swatee

    2008-03-01

    We are reporting the optimized acquisition scheme of multi-projection breast Correlation Imaging (CI) technique, which was pioneered in our lab at Duke University. CI is similar to tomosynthesis in its image acquisition scheme. However, instead of analyzing the reconstructed images, the projection images are directly analyzed for pathology. Earlier, we presented an optimized data acquisition scheme for CI using mathematical observer model. In this article, we are presenting a Computer Aided Detection (CADe)-based optimization methodology. Towards that end, images from 106 subjects recruited for an ongoing clinical trial for tomosynthesis were employed. For each patient, 25 angular projections of each breast were acquired. Projection images were supplemented with a simulated 3 mm 3D lesion. Each projection was first processed by a traditional CADe algorithm at high sensitivity, followed by a reduction of false positives by combining geometrical correlation information available from the multiple images. Performance of the CI system was determined in terms of free-response receiver operating characteristics (FROC) curves and the area under ROC curves. For optimization, the components of acquisition such as the number of projections, and their angular span were systematically changed to investigate which one of the many possible combinations maximized the sensitivity and specificity. Results indicated that the performance of the CI system may be maximized with 7-11 projections spanning an angular arc of 44.8°, confirming our earlier findings using observer models. These results indicate that an optimized CI system may potentially be an important diagnostic tool for improved breast cancer detection.

  14. Artifact reduction of ultrasound Nakagami imaging by combining multifocus image reconstruction and the noise-assisted correlation algorithm.

    Science.gov (United States)

    Tsui, Po-Hsiang; Tsai, Yu-Wei

    2015-01-01

    Several studies have investigated Nakagami imaging to complement the B-scan in tissue characterization. The noise-induced artifact and the parameter ambiguity effect can affect performance of Nakagami imaging in the detection of variations in scatterer concentration. This study combined multifocus image reconstruction and the noise-assisted correlation algorithm (NCA) into the algorithm of Nakagami imaging to suppress the artifacts. A single-element imaging system equipped with a 5 MHz transducer was used to perform the brightness/depth (B/D) scanning of agar phantoms with scatterer concentrations ranging from 2 to 32 scatterers/mm(3). Experiments were also carried out on a mass with some strong point reflectors in a breast phantom using a commercial scanner with a 7.5 MHz linear array transducer operated at multifocus mode. The multifocus radiofrequency (RF) signals after the NCA process were used for Nakagami imaging. In the experiments on agar phantoms, an increasing scatterer concentration from 2 to 32 scatterers/mm(3) led to backscattered statistics ranging from pre-Rayleigh to Rayleigh distributions, corresponding to the increase in the Nakagami parameter measured in the focal zone from 0.1 to 0.8. However, the artifacts in the far field resulted in the Nakagami parameters of various scatterer concentrations to be close to 1 (Rayleigh distribution), making Nakagami imaging difficult to characterize scatterers. In the same scatterer concentration range, multifocus Nakagami imaging with the NCA simultaneously suppressed two types of artifacts, making the Nakagami parameter increase from 0.1 to 0.8 in the focal zone and from 0.18 to 0.7 in the far field, respectively. In the breast phantom experiments, the backscattered statistics of the mass corresponded to a high degree of pre-Rayleigh distribution. The Nakagami parameter of the mass before and after artifact reduction was 0.7 and 0.37, respectively. The results demonstrated that the proposed method for

  15. Validation of Shape Context Based Image Registration Method Using Digital Image Correlation Measurement on a Rat Stomach

    DEFF Research Database (Denmark)

    Liao, Donghua; Wang, P; Zhao, Jingbo

    2014-01-01

    Recently we developed analysis for 3D visceral organ deformation by combining the shape context (SC) method with a full-field strain (strain distribution on a whole 3D surface) analysis for calculating distension-induced rat stomach deformation. The surface deformation detected by the SC method...... needs to be further verified by using a feature tracking measurement. Hence, the aim of this study was to verify the SC method-based calculation by using digital image correlation (DIC) measurement on a rat stomach. The rat stomach exposed to distension pressures 0.0, 0.2, 0.4, and 0.6 kPa were studied...... using both 3D DIC system and SC-based image registration calculation. Three different surface sample counts between the reference and the target surfaces were usedto gauge the effect of the surface sample counts on the calculation. Each pair of the surface points between the DIC measured target surface...

  16. An Intermittent Model for Intracellular Motions of Gold Nanostars by k-Space Scattering Image Correlation.

    Science.gov (United States)

    Bouzin, Margaux; Sironi, Laura; Chirico, Giuseppe; D'Alfonso, Laura; Inverso, Donato; Pallavicini, Piersandro; Collini, Maddalena

    2015-12-01

    Anisotropic metallic nanoparticles have been devised as powerful potential tools for in vivo imaging, photothermal therapy, and drug delivery thanks to plasmon-enhanced absorption and scattering cross sections, ease in synthesis and functionalization, and controlled cytotoxicity. The rational design of all these applications requires the characterization of the nanoparticles intracellular trafficking pathways. In this work, we exploit live-cell time-lapse confocal reflectance microscopy and image correlation in both direct and reciprocal space to investigate the intracellular transport of branched gold nanostars (GNSs). Different transport mechanisms, spanning from pure Brownian diffusion to (sub-)ballistic superdiffusion, are revealed by temporal and spatio-temporal image correlation spectroscopy on the tens-of-seconds timescale. According to these findings, combined with numerical simulations and with a Bayesian (hidden Markov model-based) analysis of single particle tracking data, we ascribe the superdiffusive, subballistic behavior characterizing the GNSs dynamics to a two-state switching between Brownian diffusion in the cytoplasm and molecular motor-mediated active transport. For the investigation of intermittent-type transport phenomena, we derive an analytical theoretical framework for Fourier-space image correlation spectroscopy (kICS). At first, we evaluate the influence of all the dynamic and kinetic parameters (the diffusion coefficient, the drift velocity, and the transition rates between the diffusive and the active transport regimes) on simulated kICS correlation functions. Then we outline a protocol for data analysis and employ it to derive whole-cell maps for each parameter underlying the GNSs intracellular dynamics. Capable of identifying even simpler transport phenomena, whether purely diffusive or ballistic, our intermittent kICS approach allows an exhaustive investigation of the dynamics of GNSs and biological macromolecules.

  17. MR Imaging Findings of a Primary Cardiac Osteosarcoma and Its Bone Metastasis with Histopathologic Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Se Jin; Choi, Jung Ah; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of); Chun, Eun Ju; Choi, Sang Il; Chung, Jin Haeng [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Choi, Ho Cheol [Gyeongsang National University Hospital, Jinju (Korea, Republic of)

    2011-02-15

    An osteosarcoma of cardiac origin is extremely rare, and a comprehensive description of MR imaging (MRI) findings of cardiac osteosarcoma and its metastasis in the femur have not been reported in the literature. We present a case of cardiac osteosarcoma in a 47-year-old woman and its metastasis to the femur, focusing on the description of MRI findings of the cardiac and metastatic bony osteosarcoma with a histopathologic correlation

  18. Displacement and strain field assessment of PDMS using digital image correlation

    OpenAIRE

    Mendonça, B; Ribeiro, J. E.; Lopes, H.; martins, p; M. A. P. Vaz

    2013-01-01

    The main goal of this work is the characterization of the hyper-elastic mechanical behaviour of PDMS. The special specimens of PDMS (Sylgard® 184) were tested in a bi-axial tensile machine. The displacement and strain fields were measured using a commercial digital image correlation system (ARAMIS of GOM) during the tensile test. The experimental measurements are compared with numerical simulations, which use the most popular algorithms of constitutive models to characterize the hyper-elastic...

  19. Displacement and strain field assessment of PDMS using digital image correlation

    OpenAIRE

    Mendonça, B; Ribeiro, J. E.; Lopes, H.; martins, p; M. A. P. Vaz; Gomes, S.

    2013-01-01

    The main goal of this work is to characterize the hyper-elastic mechanical behaviour of PDMS. For that, were made-up special specimens of PDMS (Sylgard® 184) for test them in bi-axial tensile machine. During the tensile test was used a commercial digital image correlation system (ARAMIS of GOM) to obtain de displacement and strain fields. These measurements are compared with numerical simulations which uses the more popular algorithms of constitutive models.

  20. Depth imaging in highly scattering underwater environments using time-correlated single-photon counting

    Science.gov (United States)

    Maccarone, Aurora; McCarthy, Aongus; Halimi, Abderrahim; Tobin, Rachael; Wallace, Andy M.; Petillot, Yvan; McLaughlin, Steve; Buller, Gerald S.

    2016-10-01

    This paper presents an optical depth imaging system optimized for highly scattering environments such as underwater. The system is based on the time-correlated single-photon counting (TCSPC) technique and the time-of-flight approach. Laboratory-based measurements demonstrate the potential of underwater depth imaging, with specific attention given to environments with a high level of scattering. The optical system comprised a monostatic transceiver unit, a fiber-coupled supercontinuum laser source with a wavelength tunable acousto-optic filter (AOTF), and a fiber-coupled single-element silicon single-photon avalanche diode (SPAD) detector. In the optical system, the transmit and receive channels in the transceiver unit were overlapped in a coaxial optical configuration. The targets were placed in a 1.75 meter long tank, and raster scanned using two galvo-mirrors. Laboratory-based experiments demonstrate depth profiling performed with up to nine attenuation lengths between the transceiver and target. All of the measurements were taken with an average laser power of less than 1mW. Initially, the data was processed using a straightforward pixel-wise cross-correlation of the return timing signal with the system instrumental timing response. More advanced algorithms were then used to process these cross-correlation results. These results illustrate the potential for the reconstruction of images in highly scattering environments, and to permit the investigation of much shorter acquisition time scans. These algorithms take advantage of the data sparseness under the Discrete Cosine Transform (DCT) and the correlation between adjacent pixels, to restore the depth and reflectivity images.

  1. Phase conjugation, isotropic and anisotropic higher order diffraction generation, and image correlation using photorefractive barium titanate

    Science.gov (United States)

    Buranasiri, Prathan

    2005-04-01

    Using barium titanate as the photorefractive material, we demonstrate phase conjugation, beam coupling, higher diffraction order generation. At small incident angles less than 0.015 radian, both codirectional isotropic self-diffraction (CODIS) and contradirectional isotropic self-diffraction (CONDIS) are generated simultaneously. At bigger incident angles approximately more than 0.2094 radian, only codirectional anisotropic-self diffraction (CODAS) are generated. On going imaging correlation is also showing.

  2. Detecting correlation functions of ultracold atoms through fourier sampling of time-of-flight images.

    Science.gov (United States)

    Duan, L-M

    2006-03-17

    We propose a detection method for ultracold atoms which allows reconstruction of the full one-particle and two-particle correlation functions from the measurements. The method is based on Fourier sampling of the time-of-flight images through two consecutive impulsive Raman pulses. For applications of this method, we discuss a few examples, including detection of phase separation between superfluid and Mott insulators, various types of spin or superfluid orders, entanglement, exotic or fluctuating orders.

  3. Adaption of the temporal correlation coefficient calculation for temporal networks (applied to a real-world pig trade network).

    Science.gov (United States)

    Büttner, Kathrin; Salau, Jennifer; Krieter, Joachim

    2016-01-01

    The average topological overlap of two graphs of two consecutive time steps measures the amount of changes in the edge configuration between the two snapshots. This value has to be zero if the edge configuration changes completely and one if the two consecutive graphs are identical. Current methods depend on the number of nodes in the network or on the maximal number of connected nodes in the consecutive time steps. In the first case, this methodology breaks down if there are nodes with no edges. In the second case, it fails if the maximal number of active nodes is larger than the maximal number of connected nodes. In the following, an adaption of the calculation of the temporal correlation coefficient and of the topological overlap of the graph between two consecutive time steps is presented, which shows the expected behaviour mentioned above. The newly proposed adaption uses the maximal number of active nodes, i.e. the number of nodes with at least one edge, for the calculation of the topological overlap. The three methods were compared with the help of vivid example networks to reveal the differences between the proposed notations. Furthermore, these three calculation methods were applied to a real-world network of animal movements in order to detect influences of the network structure on the outcome of the different methods.

  4. Welfare assessment: correlations and integration between a Qualitative Behavioural Assessment and a clinical/ health protocol applied in veal calves farms

    Directory of Open Access Journals (Sweden)

    Cornelis G. Van Reenen

    2010-01-01

    Full Text Available This study is aimed at finding correlations and possible integration among Qualitative Behavioural Assessment (QBA and a specific protocol of clinical/health evaluation. Both welfare assessment methods were based on direct animal observation and were applied in 24 Italian veal calves farms at 3 weeks (wks of rearing. Principal component analysis (PCA summarized 20 QBA descriptors on two main components (PC1 and PC2 with eigenvalues above 4 and explaining 29.6 and 20.3% of the variation respectively. PCA on residuals obtained after correcting for housing condition yielded highly similar results, indicating that the rearing environment of the calves was not an important determinant of the observer reliability of QBA. A relationship was found between QBA PC2 and the presence of signs of cross-sucking recorded during the clinical visit (presence PC2=1.11 vs. absence PC2=-1.55, P<0.001. There were no other relations between the quantitative clinical measures and QBA PC’s. The frequency of farmer, veterinarian, or industry technician visits to the veal unit significantly affected QBA PC1 and PC2 scores. These results suggest that the 2 methods provide complementary types of information and can each make valid a contribution to an integrated animal welfare monitoring scheme.

  5. DAMAGE AND FRACTURE EVALUATION OF GRANULAR COMPOSITE MATERIALS BY DIGITAL IMAGE CORRELATION METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jue; XIONG Chunyang; LI Hongju; LI Ming; WANG Jianxiang; FANG Jing

    2004-01-01

    This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steelfiber reinforced concrete, sandstone and crystal-polymer composite. The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated. The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform (WT) coefficients of the transform spectrum. The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection.Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry, both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials.

  6. Three-dimensional flow contrast imaging of deep tissue using noncontact diffuse correlation tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yu; Huang, Chong; Irwin, Daniel; He, Lian; Shang, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States)

    2014-03-24

    This study extended our recently developed noncontact diffuse correlation spectroscopy flowmetry system into noncontact diffuse correlation tomography (ncDCT) for three-dimensional (3-D) flow imaging of deep tissue. A linear array of 15 photodetectors and two laser sources connected to a mobile lens-focusing system enabled automatic and noncontact scanning of flow in a region of interest. These boundary measurements were combined with a finite element framework for DCT image reconstruction implemented into an existing software package. This technique was tested in computer simulations and using a tissue-like phantom with anomaly flow contrast design. The cylindrical tube-shaped anomaly was clearly reconstructed in both simulation and phantom. Recovered and assigned flow contrast changes in anomaly were found to be highly correlated: regression slope = 1.00, R{sup 2} = 1.00, and p < 10{sup −5} in simulation and regression slope ≥ 0.97, R{sup 2} ≥ 0.96, and p < 10{sup −3} in phantom. These results exhibit promise of our ncDCT technique for 3-D imaging of deep tissue blood flow heterogeneities.

  7. Note: Dynamic strain field mapping with synchrotron X-ray digital image correlation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, L. [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); Fan, D.; Luo, S. N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); Bie, B. X. [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Ran, X. X.; Qi, M. L., E-mail: qiml@whut.edu.cn [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Parab, N.; Sun, J. Z.; Liao, H. J.; Hudspeth, M. C.; Claus, B. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Fezzaa, K.; Sun, T. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Chen, W. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); School of Material Science Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Gong, X. L., E-mail: gongxl@ustc.edu.cn [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China)

    2014-07-15

    We present a dynamic strain field mapping method based on synchrotron X-ray digital image correlation (XDIC). Synchrotron X-ray sources are advantageous for imaging with exceptional spatial and temporal resolutions, and X-ray speckles can be produced either from surface roughness or internal inhomogeneities. Combining speckled X-ray imaging with DIC allows one to map strain fields with high resolutions. Based on experiments on void growth in Al and deformation of a granular material during Kolsky bar/gas gun loading at the Advanced Photon Source beamline 32ID, we demonstrate the feasibility of dynamic XDIC. XDIC is particularly useful for dynamic, in-volume, measurements on opaque materials under high strain-rate, large, deformation.

  8. Correlation-based imaging technique using ultrasonic transmit-receive array for Non-Destructive Evaluation.

    Science.gov (United States)

    Quaegebeur, Nicolas; Masson, Patrice

    2012-12-01

    This paper describes a novel array post-processing method for Non-Destructive Evaluation (NDE) using phased-array ultrasonic probes. The approach uses the capture and processing of the full matrix of all transmit-receive time-domain signals from a transducer array as in the case of the Total Focusing Method (TFM), referred as the standard of imaging algorithms. The proposed technique is based on correlation of measured signals with theoretical propagated signals computed over a given grid of points. In that case, real-time imaging can be simply implemented using discrete signal product. The advantage of the present technique is to take into account transducer directivity, dynamics and complex propagation patterns, such that the number of required array elements for a given imaging performance can be greatly reduced. Numerical and experimental application to contact inspection of isotropic structure is presented and real-time implementation issues are discussed.

  9. Denoising of PET images by context modelling using local neighbourhood correlation

    Science.gov (United States)

    Huerga, Carlos; Castro, Pablo; Corredoira, Eva; Coronado, Monica; Delgado, Victor; Guibelalde, Eduardo

    2017-01-01

    Positron emission tomography (PET) images are characterised by low signal-to-noise ratio and blurred edges when compared with other image modalities. It is therefore advisable to use noise reduction methods for qualitative and quantitative analyses. Given the importance of the maximum and mean uptake values, it is necessary to avoid signal loss, which could modify the clinical significance. This paper proposes a method of non-linear image denoising for PET. It is based on spatially adaptive wavelet-shrinkage and uses context modelling, which explicitly considers the correlation between neighbouring pixels. This context modelling is able to maintain the uptake values and preserve the edges in significant regions. The algorithm is proposed as an alternative to the usual filtering that is performed after reconstruction.

  10. Spontaneous rupture of the distal iliopsoas tendon: clinical and imaging findings, with anatomic correlations.

    Science.gov (United States)

    Lecouvet, Frederic E; Demondion, Xavier; Leemrijse, Thibaut; Vande Berg, Bruno C; Devogelaer, Jean-Pierre; Malghem, Jacques

    2005-11-01

    We report the clinical and imaging findings in two elderly female patients with spontaneous rupture of the distal iliopsoas tendon from the lesser trochanter of the femur. We emphasize the key contribution of magnetic resonance (MR) imaging to this diagnosis and provide an anatomic correlation. Spontaneous rupture of the distal iliopsoas tendon should be kept in mind in the differential diagnosis of acute groin pain in the elderly. MR imaging enables positive diagnosis, by showing mass effect on the anterior aspect of the hip joint, proximal muscle thickening, and abnormal signal intensity, and by demonstrating interruption of the psoas tendon, whereas the distal insertion of the lateral portion of the iliacus muscle remains muscular and is preserved.

  11. Spontaneous rupture of the distal iliopsoas tendon: clinical and imaging findings, with anatomic correlations

    Energy Technology Data Exchange (ETDEWEB)

    Lecouvet, Frederic E.; Vande Berg, Bruno C.; Malghem, Jacques [Universite Catholique de Louvain, Department of Radiology and Medical Imaging, Saint Luc University Hospital, Brussels (Belgium); Demondion, Xavier [Centre Hospitalier Universitaire de Lille, Department of Bone Radiology and Laboratory of Anatomy, Lille (France); Leemrijse, Thibaut [Universite Catholique de Louvain, Department of Orthopedic Surgery, Saint Luc University Hospital, Brussels (Belgium); Devogelaer, Jean-Pierre [Universite Catholique de Louvain, Department of Rheumatology, Saint Luc University Hospital, Brussels (Belgium)

    2005-11-01

    We report the clinical and imaging findings in two elderly female patients with spontaneous rupture of the distal iliopsoas tendon from the lesser trochanter of the femur. We emphasize the key contribution of magnetic resonance (MR) imaging to this diagnosis and provide an anatomic correlation. Spontaneous rupture of the distal iliopsoas tendon should be kept in mind in the differential diagnosis of acute groin pain in the elderly. MR imaging enables positive diagnosis, by showing mass effect on the anterior aspect of the hip joint, proximal muscle thickening, and abnormal signal intensity, and by demonstrating interruption of the psoas tendon, whereas the distal insertion of the lateral portion of the iliacus muscle remains muscular and is preserved. (orig.)

  12. Optical Measurement of In-plane Waves in Mechanical Metamaterials Through Digital Image Correlation

    Science.gov (United States)

    Schaeffer, Marshall; Trainiti, Giuseppe; Ruzzene, Massimo

    2017-02-01

    We report on a Digital Image Correlation-based technique for the detection of in-plane elastic waves propagating in structural lattices. The experimental characterization of wave motion in lattice structures is currently of great interest due its relevance to the design of novel mechanical metamaterials with unique/unusual properties such as strongly directional behaviour, negative refractive indexes and topologically protected wave motion. Assessment of these functionalities often requires the detection of highly spatially resolved in-plane wavefields, which for reticulated or porous structural assemblies is an open challenge. A Digital Image Correlation approach is implemented that tracks small displacements of the lattice nodes by centring image subsets about the lattice intersections. A high speed camera records the motion of the points by properly interleaving subse- quent frames thus artificially enhancing the available sampling rate. This, along with an imaging stitching procedure, enables the capturing of a field of view that is sufficiently large for subsequent processing. The transient response is recorded in the form of the full wavefields, which are processed to unveil features of wave motion in a hexagonal lattice. Time snapshots and frequency contours in the spatial Fourier domain are compared with numerical predictions to illustrate the accuracy of the recorded wavefields.

  13. Dynamic MR imaging of internal derangements of the temporomandibular joint: correlation with clinical signs and symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Ah; Chun, Eun Ju; Kim, Yoo Kyung; Yoo, Jeong Hyun; Choi, Hae Young; Kim, Hyun Jin [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of); Chung, Eun Chul [Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-01-01

    To evaluate the correlation between findings of dynamic magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) and clinical findings in patients with internal derangement of the TMJ. Dynamic MR images of 130 joints of 65 patients (17 men and 48 women aged 14 to 74; mean age, 34) with internal derangement of the TMJ were obtained using a 1.5-T MR imaging system. MR findings of anterior displacement, disc deformity and degenerative change were correlated with clinical findings including joint pain, clicking sound, crepitation and maximal mouth opening (MMO). Among 62 joints with TMJ pain, 32 showed anterior displacement without reduction, 15 showed disc deformity and 19 showed degenerative change. Among 49 joints in which there was a clicking sound, 24, 8 and 12 joints, respectively, showed the above-mentioned findings, while in seven with crepitation, these same findings were evident in five, six and four joints, respectively. Bilateral and unilateral joint disorders were observed in 17 and five patients, respectively, among 22 with MMO less than 30mm and in 11 and 18 of 42 patients with MMO between 30mm and 60mm. On MR imaging, patients with MMO less than 30mm usually showed bilateral joint disorders and those with crepitation showed chronic change. This indicates that there is high association between clinical findings of internal derangement of TMJ and MR findings.

  14. Correlation of magnetic resonance imaging findings of spinal intradural extramedullary schwannomas with pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeo Ju; Park, In Suh; Yoon, Seung Hwan; Choi, Suk Jin; Kim, Youn Jeong; Kang, Young Hye; Lee, Ha Young; Kim, Woo Chul; Han, Jun Gu; Cho, Soon Gu [Inha University Hospital, Incheon (Korea, Republic of)

    2015-06-15

    To evaluate the magnetic resonance imaging (MRI) findings of spinal intradural extramedullary schwannomas with pathologic correlation and to determine whether these schwannomas share the imaging features of schwannomas in the peripheral nerves. The MRIs of 17 cases of pathologically proven spinal intradural extramedullary schwannomas were reviewed retrospectively, and cystic changes, enhancement, and intratumoral hemorrhage of the tumors were evaluated. Imaging features known to be common findings of schwannoma in the peripheral nerves, such as encapsulation, the target sign, the fascicular sign, and visualization of entering or exiting nerve rootlets, were also evaluated. The histopathology of the tumors was correlated with the MRI findings. Cystic changes were detected in 14 cases by MRI and in 16 cases by pathology. The most common pattern of enhancement was a thick peripheral septal pattern (70.59%). Intratumoral hemorrhage was detected in four cases on MRI, but in all cases on pathology. Encapsulation was observed in all cases. The fascicular sign was seen in only four cases, and thickening of an exiting rootlet was visualized in one case. None of the cases showed the target sign. Spinal intradural extramedullary schwannomas were typical encapsulated cystic tumors and had few imaging features of schwannomas in the peripheral nerves.

  15. Optical Measurement of In-plane Waves in Mechanical Metamaterials Through Digital Image Correlation

    Science.gov (United States)

    Schaeffer, Marshall; Trainiti, Giuseppe; Ruzzene, Massimo

    2017-01-01

    We report on a Digital Image Correlation-based technique for the detection of in-plane elastic waves propagating in structural lattices. The experimental characterization of wave motion in lattice structures is currently of great interest due its relevance to the design of novel mechanical metamaterials with unique/unusual properties such as strongly directional behaviour, negative refractive indexes and topologically protected wave motion. Assessment of these functionalities often requires the detection of highly spatially resolved in-plane wavefields, which for reticulated or porous structural assemblies is an open challenge. A Digital Image Correlation approach is implemented that tracks small displacements of the lattice nodes by centring image subsets about the lattice intersections. A high speed camera records the motion of the points by properly interleaving subse- quent frames thus artificially enhancing the available sampling rate. This, along with an imaging stitching procedure, enables the capturing of a field of view that is sufficiently large for subsequent processing. The transient response is recorded in the form of the full wavefields, which are processed to unveil features of wave motion in a hexagonal lattice. Time snapshots and frequency contours in the spatial Fourier domain are compared with numerical predictions to illustrate the accuracy of the recorded wavefields. PMID:28205589

  16. A methodology for time-frequency image processing applied to the classification of non-stationary multichannel signals using instantaneous frequency descriptors with application to newborn EEG signals

    Science.gov (United States)

    Boashash, Boualem; Boubchir, Larbi; Azemi, Ghasem

    2012-12-01

    This article presents a general methodology for processing non-stationary signals for the purpose of classification and localization. The methodology combines methods adapted from three complementary areas: time-frequency signal analysis, multichannel signal analysis and image processing. The latter three combine in a new methodology referred to as multichannel time-frequency image processing which is applied to the problem of classifying electroencephalogram (EEG) abnormalities in both adults and newborns. A combination of signal related features and image related features are used by merging key instantaneous frequency descriptors which characterize the signal non-stationarities. The results obtained show that, firstly, the features based on time-frequency image processing techniques such as image segmentation, improve the performance of EEG abnormalities detection in the classification systems based on multi-SVM and neural network classifiers. Secondly, these discriminating features are able to better detect the correlation between newborn EEG signals in a multichannel-based newborn EEG seizure detection for the purpose of localizing EEG abnormalities on the scalp.

  17. IMAGE COMPLETION BY SPATIAL-CONTEXTUAL CORRELATION FRAMEWORK USING AUTOMATIC AND SEMI-AUTOMATIC SELECTION OF HOLE REGION

    Directory of Open Access Journals (Sweden)

    D. Beulah David

    2015-08-01

    Full Text Available An image inpainting scheme has been proposed that utilizes the spatial contextual information approach for image completion. The domain to be inpainted is smooth for texture images. It can be inpainted using exemplar and variational methods. In proposed method, the regions to be removed from the image are segmented and pull out of the image where it is tenure as hole. As the hole in the image to be inpainted is an unsupervised approach, we are computing the pixel in the holes using spatial contextual correlations. The method’s efficacy is embodied by real images.

  18. Inverse computational feedback optimization imaging applied to time varying changes in a homogeneous structure.

    Science.gov (United States)

    Evans, Daniel J; Manwaring, Mark L; Soule, Terence

    2008-01-01

    The technique of inverse computational feedback optimization imaging allows for the imaging of varying tissue without the continuous need of a complex imaging systems such as an MRI or CT. Our method trades complex imaging equipment for computing power. The objective is to use a baseline scan from an imaging system along with finite element method computational software to calculate the physically measurable parameters (such as voltage or temperature). As the physically measurable parameters change the computational model is iteratively run until it matches the measured values. Optimization routines are implemented to accelerate the process of finding the new values. Presented is a computational model demonstrating how the inverse imaging technique would work with a simple homogeneous sample with a circular structure. It demonstrates the ability to locate an object with only a few point measurements. The presented computational model uses swarm optimization techniques to help find the object location from the measured data (which in this case is voltage).

  19. VOLUME STUDY WITH HIGH DENSITY OF PARTICLES BASED ON CONTOUR AND CORRELATION IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Tatyana Yu. Nikolaeva

    2014-11-01

    Full Text Available The subject of study is the techniques of particle statistics evaluation, in particular, processing methods of particle images obtained by coherent illumination. This paper considers the problem of recognition and statistical accounting for individual images of small scattering particles in an arbitrary section of the volume in case of high concentrations. For automatic recognition of focused particles images, a special algorithm for statistical analysis based on contouring and thresholding was used. By means of the mathematical formalism of the scalar diffraction theory, coherent images of the particles formed by the optical system with high numerical aperture were simulated. Numerical testing of the method proposed for the cases of different concentrations and distributions of particles in the volume was performed. As a result, distributions of density and mass fraction of the particles were obtained, and the efficiency of the method in case of different concentrations of particles was evaluated. At high concentrations, the effect of coherent superposition of the particles from the adjacent planes strengthens, which makes it difficult to recognize images of particles using the algorithm considered in the paper. In this case, we propose to supplement the method with calculating the cross-correlation function of particle images from adjacent segments of the volume, and evaluating the ratio between the height of the correlation peak and the height of the function pedestal in the case of different distribution characters. The method of statistical accounting of particles considered in this paper is of practical importance in the study of volume with particles of different nature, for example, in problems of biology and oceanography. Effective work in the regime of high concentrations expands the limits of applicability of these methods for practically important cases and helps to optimize determination time of the distribution character and

  20. Neural correlates underlying mental calculation in abacus experts: a functional magnetic resonance